I think people dismissing Gane do so more to delegitimize Jones as a HW champ. If Jones hadn't man-handled him so easily on the way to a win, they'd still be talking about him like they did before their fight. I seem to remember predictions that he'd expose Jones.
No one could beat him until Ngannou did it, because his striking was that much better than everyone else, and even Francis chose to go for the wrestle-fuck decision path rather than stand and trade with him, which I thought was telling and somewhat remarkable.
He's very good. So is Aspinall. Aspinall has more ways to win, so I'd have to say he's favored. If Gane can keep it on the feet, mostly in the middle of the cage, and can keep it at distance, that's his path to winning.