Board Thread:Game Discussion/@comment-5012038-20130518014717/@comment-99.229.171.230-20130519000126

Hasbro does not have those trademarks, hence why the upcoming figure (and the Legends version from a while back) of Trailbreaker is called Trailcutter and not Trailbreaker or Trailblazer (which is his much less common name). There's also Grapple who had to have his name changed to Grappel, among others mentioned. It is indeed a licensing issue, though the reasoning is not because words were too general (though this has happened before).

As for Megatron, his alt mode being a tank is simply an evolution of his character. Having the alt mode of a handgun that magically grows and shrinks when transformation occurs stopped making sense even before G2 came about. Optimus also had a significant design update.