He transformed into God a second time, entirely by himself, in the original movie.
It as also never said that Goku could never get Super Saiyan God again especially since he absorbed it, something that no one expected to happen and Super Saiyan God Super Saiyan was Goku recapturing godhood. But, I would have liked an explanation about how long Goku had Super Saiyan God. Like, did he have it since Battle of Gods or did he relearned it from training with Whis.
Overall, I'm not happy about Super Saiyan God being back and it feels just as unneeded as the manga, but it did have a few blessings upon it return:
- It finally killed that stupid two-base theory that has been used to downplay everyone, so good ridden.
- Super Saiyan God Super Saiyan is the only form with ki control, ignoring that Goku didn't kill his wife in the Cell Saga when he was Super Saiyan and had sex with her.
- Slaythe will love this, people will stop downplaying 17, like saying Goku could have beating him with Super Saiyan 3.
- It confirmed once and for all that Super Saiyan God Super Saiyan > Super Saiyan God, despite the manga and narrator in the Resurrection 'F' Saga stating that it was.
- And I got to read salty Vegeta fans whining about Goku stealing Vegeta's gimmick from the Super manga, which was a stupid gimmick anyway but anything that makes Vegeta's fans cry tend to make me happy.