In order to reconcile the mistake done in "Dragon Ball Super: Super Hero", the next manga arc should...

[Geraldo]

Use Majin Buu again in a serious manner to explain how and why the new Red Ribbon Army knew about his existence in the movie despite the wish that was made six months after Kid Buu's death to erase him from the memories of all the Earthlings sans the Z-Fighters and their peers.

Yes, I am fully aware that is yet another mistake by Akira Toriyama who wrote the script for DBS:SH. But Toyotaro can fix it.

Canonical Thin/Fit Buu, here we come!

[Jack Bz]

Maybe they found old intel written about him at the time/some recordings of him etc and while they didn't remember him they managed to piece things together that majin boo was the one that they were saved from (as far as I remember they still remember being saved by Mr Satan from *something*).

[theherodjl]

I could be misremembering it but didn't the guy that had Broly cloned also somehow have knowledge that not only was Broly a Saiyan but the legendary Super Saiyan too? Maybe there's an underground network of humans that still remember all the weird stuff that has happened on Earth due to the Z Senshi, keeping detailed files and audio/video evidence that it happened?

[Xeogran]

Maybe there's an underground network of humans that still remember all the weird stuff that has happened on Earth due to the Z Senshi, keeping detailed files and audio/video evidence that it happened?

That would be interesting actually, gives the Earth a new fraction without resorting to recycling Red Ribbon over and over again. I like that!

[Geraldo]

Maybe there's an underground network of humans that still remember all the weird stuff that has happened on Earth due to the Z Senshi, keeping detailed files and audio/video evidence that it happened?

That would be interesting actually, gives the Earth a new fraction without resorting to recycling Red Ribbon over and over again. I like that!

The MB Army from that old 1980s Dragon Ball video game, led by Lord Jaguar, I presume. With MB standing for "Memory Blokes".

[Zephyr]

Maybe they found old intel written about him at the time/some recordings of him etc and while they didn't remember him they managed to piece things together that majin boo was the one that they were saved from (as far as I remember they still remember being saved by Mr Satan from *something*).

I think this would make sense. Given that they have footage of Trunks fighting Freeza, I don't see why they wouldn't also have footage of Boo terrorizing the planet.

[theherodjl]

Given that Gero had spybots observing Goku and the team for years, it's not out of the question that someone else on Earth might be observing things from afar with technology or even magic/ESP. Dragonball does has a habit of recollecting past events in whatever way necessary as a result of some character bringing it up to advance the plot. It could even lead to things that have been forgotten returning to either benefit the team or cause trouble in unexpected ways.
We might learn that Earth actually has some esoteric significance to the universe that even Shin & Rou Kaioshin aren't aware of because it goes above even their paygrade.

[Koitsukai]

The RR had been keeping an eye on odd stuff, probably with their own spybots or with Gero's leftovers, so it's easy to assume they have footage of Fat Buu, probably around the time Babidi learned that the kids he was looking for lived in Capsule Corp, knowing when or how to track him.
Buu's house wasn't a secret, Mr. Satan and those murderers went there, so sending a spybot to his place isn't far-fetch either.
Since they have Mecha Freeza on tape, 10 years before Buu was released, they most definitely had footage of Buu as well.

They should've wished to erase Buu from people's memories and also from every database, including spybots.

[Geraldo]

But the very existence of the Red Ribbon Army after the specific wish to only revive those who weren't evil and who were killed during the Majin Buu crisis is yet another mistake made by Akira Toriyama.

If Magenta and Carmine were working behind the scenes all those years since Perfect Cell was defeated to revive the RRA then they were undoubtedly evil, and so were their recruits.

[Zephyr]

If Magenta and Carmine were working behind the scenes all those years since Perfect Cell was defeated to revive the RRA then they were undoubtedly evil, and so were their recruits.

Not to Porunga they weren't, apparently. Alternatively, the Viz translation has Dende specify "the very evil ones"; so you could say that Bobbidi and Dabura (the people whose revival the wish's phrasing was meant to disallow) were very evil, but Magenta and Carmine were only normal evil.

[Koitsukai]

If Vegeta, who had just blown up half a stadium to piece off Goku, was considered a good guy and brought back, then Carmine and Magenta were probably nicer than Bagger Vance in Porunga's eyes.