The attack is non-canon, anime-only. Also, if it acted any way like a black hole, it wouldn't have pushed them down like a gravity chamber, but pull them inward to a point. Also, people outside the attack would have also felt the pull... The attack is an exaggeration when they compare it to a black hole. Not to mention the stage didn't collapse...

There's a reason even die hard fans don't think it was a real black hole, with the EXACT mention of Vegeta incapable of lifting his enemy. It's just gravity... But no where near that of a black hole. Your math is openly contradictory to the source material you show.

Initially, Super Saiyan was divided into 5 grades. Grade 5 (originally called "Supa Saiya-jin Dai-Go Dankai") was never given a name in the Cell Saga. It was nicknamed "True Super Saiyan" in either the Daizenshuu or the Trunks Anime Special booklet. Akira Toriyama never named it Super Saiyan 2, just "a power beyond a Super Saiyan". The interview happened before its reintroduction in the Majin Buu saga... So Akira Toriyama was right to name "Super Saiyan 3" as its second iteration - the fans dubbed Gohan's achievement as Super Saiyan 2. So when Goku was fighting Majin Buu he introduced the Grade 4 form as just Super Saiyan and the Grade 5 form as "Supa Saiya-jin Tsu" (Super Saiyan 2).

He never forgot this, he was just unaware of the fans already dubbing it. He was gaslit before gaslighting was a thing. Lol.