I think that there were some benefits to not retooling the Voyager head for TakaraTOMY, including:
- Cheaper :p
- The Hasbro head is still G1 toy-accurate; the Brainstorm toy was identical in Japan. This is different from say the head of Cerebros/Fortress; the Hasbro figure is based on the way that Marvel/Sunbow drew him which looks nothing like the G1 toy, and the Japanese cartoon was more toy accurate. Hence it would have too little appeal for the Japanese market which was probably why TakaraTOMY went with a more toy/anime-accurate head for their Fortress/Cerebros.
- There are Japanese fans who follow the IDW comics.
- The retooled head on the Deluxe now gives Japanese fans who own the Voyager an additional excuse to buy the Deluxe. ;) I'm not in a position to criticise this considering that I recently bought PM Optimus Prime and I'm still considering getting Ginrai. :p