Tyrannosaur NOT Tank.

Personally, whilst I understand the argument for Grimlock being a Tank, IMO he is far superior as a T-Rex and that is what I remember him as, not a Tank which is a really unnecessary Retcon.
Also, looking at the artwork that has been released so far; I don't see anything suggesting they're on Cybertron - Giving reason for the differing Bot/Alt modes from WFC 1.
(I realise what the Activision Announcement Info says, this artwork suggests otherwise )