My list is boring, but probably more realistic

Optimus Prime: He needs to be done right, and his presence as a potential icon is far more important than people give credit to.

Bumblebee: Marketing reasons aside he acts as a decent protagonist and not including him after Bumblebee seems counterproductive for the reboot. Like, why make Hot Rod a protagonist when Bumblebee can fulfill that role and has already has a head-start in character development?

Arcee: A well-written TFP Lancer type team member would go far. I don't think she should be executed in the same way TFP's character was, but the idea of her fulfilling the role of the Lancer seems like a good bet.

Ironhide: Because he can cover a lot of ground as being ornery, a warm team-dad presence, and also act as the "big guy" of the team to give the Autobots a little edge. Essentially he can fulfill the roles of both Ratchet and Bulkhead. He can be worfed-- with reason-- to give the Decepticons some presence. And his presence would give Optimus someone to interact with on the same level, whereas there would remain a certain power-dynamic with the younger Arcee and Bumblebee.

Starscream: Because I think Megatron can indeed be saved for later, only making brief appearances in the shadows. Both TFA and TFP had Megatron take a backseat for some time in order to build up to his natural appearance, and I think it can be done in a similar vein for the movies. Since Starscream is the next most known Decepticon with power it just makes sense for him to be the main antagonist for the start.

Soundwave: Channeling some more TFP inspiration for his role here, but mostly he'd be included because his gimmicks allow for more of the technological warfare seen in the first movie and allows for a lot of flexibility in the kinds of things the Decepticons can accomplish ala hacking and sabotage. The contrast between Starscream's vainglorious ranting and Soundwave's quiet demeanor, as seen in TFP, would also help add to the diversity of personalities in the Decepticons, and the two as a pair would act as a good substitute for Megatron.

Shatter: I know she gets consumed in an explosion and probably blown apart but I could still see a reasonably framed "this is how she survived" sequence in which she was just left horribly, torched and, uh, shattered, but is brought back to be a Cyberverse Shadow Striker kind of character with a vendetta against Bumblebee. She also seems like the kind of character that would act as a constant thorn in Starscream's side. She was also a huge threat in Bumblebee and her return would make for a huge addition to the Decepticon ranks as previously established. She also covers a lot of ground as A: a heavy hitter and triple changer, B: a character that can serve as a rival to Bumblebee, and C: a sort of Starscream to Starscream, as seen in characters like Airachnid or Slipstream.

Cyclonus/Bludgeon: Struggled hard to think of a fourth member that would make sense. I ruled out Knock Out because of Shatter and Soundwave's combined tech skills and I don't feel like more than one of the Decepticons should be able to turn into a car. Barricade too, since Shatter would fulfill the role of Bumblebee's arch rival. Lugnut could potentially fill this role, though part of me feels he could be better suited as the right hand to Megatron, should he ever show up, and both Soundwave and Shatter would probably already fulfill the roles of underminers to Starscream's authority. We would already have a triple changer in Shatter, so Blitzwing is out. TBH I think having one mindless bloodthirsty Decepticon to act as a bruiser would have been perfect, so I think someone like Bonecrusher or Brawl could definitely fulfill this role, though the characters themselves are kind of boring in concept. Ultimately though I am split between Cyclonus and Bludgeon, since then you can make them staunch patriots and bring in "Decepticon Honour" as a charming contradictory concept. They wouldn't be quiet like Soundwave, or methodical like Shatter. Instead they would be loud patriots proclaiming supremacy of the Decepticon Empire and recite their Decepticon codes of honour, all the while cutting down Autobots without any hesitation or fanfare, leading to some entertaining notions of how the Decepticons view and glorify violence. They wouldn't be really smart, or see the full picture, but they would be loyal to the cause, perhaps blindly so. I am split between Cyclonus and Bludgeon in particular because I think Cyclonus is more interesting, and there is the potential for an arc or side-change with him, but there are already two jets, and Bludgeon can have his marvel personality of "HAH! You cannot defeat a master of metallikato! Your moves are like in slow motion!" Which I think could make him a fun character if hammed up.

 

Autobots.
Optimus Prime
Abejorro
Ocultar hierro
Jazz
Decepticons
Megatron
Starscream
Onda de choque
Soundwave

 

Autobots:
Arcee
Breakaway
Bumblebee
Optimus Prime
Decepticons:
Blitzwing (using that fan theory of Dropkick, Shatter, and Blitzwing being rebuilt)
Barricade
Shockwave
Starscream

For the Autobot team, I wanted to have some variety. I feel like Bumblebee and Optimus are a given considering the first film set that up, and to have them completely absent would feel weird. So, that left 2 open spots for other Autobots. Arcee felt like a good choice because she’d add some nice chemistry between other bots. I chose Breakaway because 1) I like Breakaway 2) his design is too good to only appear in a video game tie-in to RotF and could fit pretty well in the new universe and 3) we are in desperate need of an Autobot that can fly.

For the Decepticons, I purposefully wanted to omit Megatron from the roster because I feel that he should be saved for a later film. Think the buildup to his appearance in 2007 but bigger. So, that left me with the next best thing, Starscream. I feel like there could be some sort of power-struggle going on amongst the Decepticons like in Reign of Starscream. Shockwave, Barricade, and Blitzwing would be somewhat hesitantly following his orders. I mostly wanted a diverse and interesting cast of bots. 3-head Blitzwing would be cool, and Barricade coming back would be nice as well. Shockwave could be the “dangerous one.”

 

Optimus, Bumblebee, Arcee and wheeljack, and on the Con Side Megs, Starscream, Soundwave and Shockwave.

I'd love to see them banter, even if it means simplifying the designs

 

Decepticons: Blitzwing, Starscream, Lugnut, and Megatron
Autobots: Optimus, Bumblebee, Bulkhead, Prowl,


I'd add in Blackarachnia and Ratchet to the toyline...yes I picked the Animated Line-up