By AT you mean Akira Toryiama? The only thing he retconned was GT and that wasn't even made by his hand.
lol you clearly have been left out of the loop
-King Kai having a planet by the end of the series
-Bibidi finding Buu as oppose to creating him
-Literally every single time a new type of god is introduced retcons the other one claiming to be the strongest same with overseeing "everything" turns out there's always someone higher than them overseeing more
- It has been proven time and again that AT wanted to end the series but kept being forced to continue it (23rd Budokai, Frieza saga and the Cell saga was meant to be an ending it even had an epilogue then the Buu saga now we have movies)
- The SSJ multipliers going from x50 to x3
- AT wrote a small GT manga and even approved it, everything in BOG is contradicting GT
- The super saiyan levels, AT said himself referred to Gohan fighting Cell as "A super saiyan level 5" but then the idea came up to make another transofrmation so he just decided to re-number it 2 and then forget all about what the ascended levels Vegeta and Trunks accomplished.
- Piccolo was a demon, then he became an alien
- Saiyans were killed by a meteor shower by their own Planet's Kami, even King Kai confirmed it then it was changed to Frieza to make his villain status more personal
-Vegeta knew about Beerus yet always was and stated to be afraid of Frieza because he thought he was the most dangerous person in the universe
-The Kais have been there since the beginning of time and created with the universe, this was changed to them being kittening apples grown from a tree