I think Jon accounted for ring rust with the choice of opponent: if he came back vs Ngannou he would need to be perfect for 25 min to leave with a win and his head still attached. But vs Gane he can probably eat some shots and still win with grappling or get a Reyes style gifted decision after being lit up early.
My prediction is it’s going to be another controversial decision/robbery for Jones (judges paid off by Dana). Gane will unofficially win 3 rounds in everyone’s eyes so he won’t lose any stock, but by having Jones win it will create more money fights at HW, that’s the best case outcome for the UFC so that’s surely the tentative plan unless a finish happens.
Let’s be clear on one thing, Gane cannot win a decision unless he pitches a total shutout like what Hill did to Glover. Jones is walking into the arena up 2-0 on the cards so just winning 3 or even 4 rounds won’t be enough, he needs a finish or to win all 5 rounds. UFC will not let the judges give a big star/undefeated legacy fighter like Jones an L, unless it’s a total domination where a robbery would be called out for the corruption that it is.