So pretty much something that some fans are against regarding the Transformers Cinematic Universe is that there are no more A-List Decepticons moving foward (Expect for Megatron) and few have used this as an example as to why it should be rebooted. but do we really need the A-List Decepticons to move foward?. For me the awnser is no, we dont need the A-List Decepticons for the Cinematic Universe to work, look we have plenty of Decepticons and Evil Cybertronians in the Transformers lore that they could chose from to be the antagonist of future movies, we've had stories that didnt focused on Starscream, Soundwave, Shockwave or Megatron for that matter and they have worked. you can make a good story or arc without the A-List Decepticons, lesser known Decepticons can be as good as the A-List Decepticons if written well. Sure if they had known they would've made more movies after DOTM, theres no doubt they would've survived, but what is done is done (unless they find a way to bring them back), but again the cinematic universe dont need them. its like saying Spider-Man or Batman movies cant work if the A-List villains were not front and center of the franchise or had a huge presence.