After Majin Boo (or Kid Boo to be precise) was defeated, Goku wished to erase the memories of Majin Boo (likely including Babidi and his crew) from everyone on Earth with the sole exception of Goku's friends and family.
This begs a question of how many memory wiped from 25th Tenkaichi Budokai, which is still part of the arc.
Spopovich and Yamu were controlled under Babidi, played very important role during the Tournament, include severely damaging Videl and draining Gohan's energy, resulting majority of the competitors left, changed the format to Battle Royale.
After Mr. Satan won, Majin Vegeta killed several audience, yet 10 years later, Vegeta was able to participate in 28th Tournament without problem; though, Majin Vegeta was in Super Saiyan form and Piccolo was able to enter 25th Tournament under Ma Junior, despite that alias was already used in previous tournament.
Here's my guess of which memory were retained and wiped from 25th Tenkaichi Tournament
- Kid Division [RETAINED]
- Preliminary "Punch Machine" [RETAINED]
- Yamu and Spopovich [RETAINED?]; their current status is unknown, but they most likely were not brought back.
- Krillin vs. Pintar, Shin vs. Piccolo [RETAINED]
- Videl vs. Spopovich [RETAINED?] - kind of awkward for Videl fan to see that remembered.
- Gohan vs. Kibito (Gohan’s Great Saiyaman reveal, draining energy by Yamu and Spopovich, and majority competitors left) [RETAINED]
- Battle Royale [RETAINED]
- Majin Vegeta rampage [WIPED]
The only event from tournament that was wiped is probably Majin Vegeta rampage for killing audience.
What do you think?