We dont know for sure there will be later seasons and he is already listed as having a VA for the 2 seasons already produced so id say its a safe bet he appears and speaks by the end of season 2.

As for getting a toy there are based of current info 26 transformer characters in seasons 1 & 2 and there will be 9 voyagers and 15 deluxes thats 24 figures we know there is at least 2 versions of Prime and Megatron which brings it down to 22 if the 3 Leader toys are for animated thats back up to 25 which is why A). I seriously hope we dont get anymore versions of existing characters and B). Why I hope the constructicons are packaged togethor as it would allow for all of te currently know characters to get toys within the already released numbers.

Not to mention that while shockwave may not be a 'major' character his VA is part of the ongoing cast thus making return appearances easy IMO the most likely characters to miss out on toys will be Wreck gar and Blurr as their VAs arent part of the core cast thus making return appearances more difficult.

 

we don't