I agree.
They're trying to visually tell a story with his changing aesthetic. But Hasbro seems hell bent on shoehorning the WFC/FOC into their Prime continuity (despite WFC's 5,492 nods and references to the G1 cartoon and comics) so why they'd head into boxier G1 territory is a mystery. Megatron's design has been revised also, but seems even more spiky and Bayified than before.
Honestly, I'd prefer if it didn't lead into either G1 or Prime, and instead led into it's own new version of a G1 continuity. If they did an eventual game that led to the Autobots and Cons awakening on earth, that'd be awesome. Even better if they used the existing Classics designs for characters where applicable - an easy win for Hasbro with toy tie-ins while giving a second chance to anyone who missed out on crucial Classics characters first time around. But that's just me wishing out loud.