Funny you should mention IMVU, as I'm on it
Hasbro does own the trademark
to Cybertron, yes. This little promotion could be in violation of trademark law, as real money is paid despite being virtual goods.
However, the name itself has never been trademarked I see, and I don't know if that constitutes to Fair Use. Also, "Cybertrons" is used to describe the avatars instead of "Autobots", and not the planet. That may make it hard for Hasbro to make a case.
"I have Autism and I'm proud of it!" - Myself
Top 5 Priorities:
1) BW Neo X-7 Elphaorpha
2) RiD 2001 Dreadwind & Smokejumper
3) RiD 2001 Destructicons Bludgeon & Scourge
4) Universe 2003 Night Slash Cheetor
5) BW Convobat (red) & Megalligator (purple)
The resident Rewind... well, half of one
- Jelze Bunnycat =:3