There seems to be a bit of a difference, even though both involve asking questions. To quote wiktionary:

sealioning (uncountable)
A type of trolling or harassment that consists of pursuing people with relentless requests for evidence, often tangential or previously addressed, while maintaining a pretense of civility and sincerity (“I’m just trying to have a debate”), and feigning ignorance of the subject matter, in order to wear down an opponent and incite angry responses that will discredit them.

Apparently coined by this webcomic:

JAQ off (third-person singular simple present JAQs off, present participle JAQing off, simple past and past participle JAQed off) (slang, derogatory) To ask loaded questions inviting someone to justify their views or behaviours, in an attempt to make tangential claims of little verisimilitude appear acceptable.

So the way I understand it, “JAQing off” is when you’re trying to guide your audience towards a certain conclusion without stating it outright (e.g. “Are the official numbers of holocaust victims really as solid as people claim? Are there alternative historical interpretations? I’m just asking questions here, not implying anything folks.” when you think just saying “The holocaust didn’t happen!” might make it too obvious you’re a Nazi), while sealioning is more about annoying the other party and trying to make them look bad/unreasonable and yourself polite and reasonable in comparison (e.g. “I’m just curious, is there any actual evidence that fascists are inherently bad people, as you claim? As a person with no opinion on the matter, I would just like to have an honest and open debate on this subject.” so when people reply with something like “Fuck off, fascist!” you can say “Wow, so much for the tolerant left.”). Both tactics are frequently applied by online trolls, especially of the far right, but they have somewhat different goals.

It’s precisely what everyone said would happen.

I don’t disagree with your general point, but I remember that there were many people (on reddit, but also on lemmy) who said there would be lots of power-hungry redditors just waiting to take over and that the admins would thus have no trouble at all finding replacements.