They have to keep using the names if they want to use them.

Ref. The Shockblast saga. That name existed entirely because Hasbro couldn't use 'Shockwave' for a period of time and once they got it back they've clamped down on it hard.

Most famously the trademarking names issue affected the He-man character Fisto who had his name 'lifted' by Kit Fisto from the Star Wars toy line.

Sharing names between Transformers and GI Joe kept quite a number of more obscure characters' names in circulation available to Hasbro.

 

His art style is still so singular and emotional.