No I think Mr. Buu was able to somehow reasborb Fat Buu's power. Just think about Kid Buu being Buff Buu for a second. It doesn't really make sense. Something with how he went Buff and how he lost it perhaps lead to Mr. Buu attaining his old power again.
Ridiculously more impressive than Vegeta. Mr. Buu makes Kid Buu's whole face drop, he becomes enraged and Mr. Buu is able to put up a fight with an angry Kid Buu.
There's no way someone less that Evil Buu can do that man.
No, I think what is more likely that AT forgot that there is a difference between Fat and Good. Also, our one chance of making up for his mistakes is Kid Buu going Buff and then mysteriously losing that power.
Wouldn't it make sense for Good Buu to somehow reabsorb South Kaioshin's power? I mean, where did South Kaioshin's influence go then?
The entire writing for Boo made no sense. Pulling out Good Boo should have turned him into Grey Boo.
I would buy your theory if Good Boo had featural differences, as South Kaioshin Boo changed Pure Boo.
All that I know is that Good Boo only took some of Fat Boo's power, so it doesn't seem plausible for him to gain more than his maximum (what was displayed vs Grey Boo). Good Boo seemed to be all Dai Kaioshin, hence his innocence.