>>530428409
Unfortunately that's what Toriyama was implying with the whole "Goku was a rowdy baby but once he got hit on the head he became nice". Saiyans were so evil they implanted memories of the mission on babies and Goku needed to forget about it to not be evil.

>>530428790
It's a licensing issue. Manga exclusive attacks have made their way in games, but new forms and characters didn't.

I suspect part of the reason is voice acting related, I think Toei calls the shot in who's voicing who, so someone like Moro has to first be voiced in an anime before showing up in games, but even if I'm right it doesn't explain why transformations are offlimits...