That's wishful thinking on your part. The FF is not going back to Marvel unless Disney opens up that wallet. For some reason, and out of nowhere, I got reminded of Crash bandicoot on the gaming side, which is in a similar situation. While they are not exactly the same use case (i.e. there is no leasing or licensing of an IP like there is with FF), they are similar enough.
Everybody knows FF's story on this board, so I'll skip it. Crash Bandicoot is an old franchise, originally developed for the old Playstation 1. Originally developed by Naughty Dog on work for hire (sounds familiar?) where Universal owned the rights to the franchise. Sony bought Naughty Dog (the developer), Activision later bought Universal (the rights owner). The first 3 games (plus the kart racing game) were superb. I remember gawking over them as a kid and at the time, the sales of Crash rivaled those of Nintendo's Mario.
Since Sony bought the developer but didn't own the rights, they weren't about to keep developing games for IPs they didn't own, so they started creating their own IPs, and the world was forever grateful because TLOU and Uncharted came out because of it. Activision, though, tried to milk Crash due to its high popularity. The games all sucked, but they kept milking them (any gamer knows that Activision is known to milk franchises to the ground). From "Wrath of the Cortex" in 2001, the games started sucking. Sales started to drop. By 2008, they had released like 5 or 6 games across different systems and, what was once a competitor to Mario in quality and sales, was now a joke whereas Mario was a much better and much better selling game.
Activision then stopped releasing Crash games because they sucked too much and no one wanted to buy them. From 2008 until 2016 there were no games released or announced. Fans started digging and seeing how long Activision had to use the trademark or they would lose it (kinda what we did here). Fans started being vocal about Activision selling the rights to Sony so ND could do the game justice (sounds familiar?). In 2016 Activision announced Crash Trilogy remake for PS4. They didn't sell the rights and created the game in-house. It is the first Crash game to review and sell well since 1999 and it is making Activision money, there's energy around the Crash IP, and - most likely - more games in the franchise are coming.
Moral of the story. Fox will try with FF until Disney pays them. They still regret losing DD, they are still salty about not giving an opportunity to buy Lucasfilm. In both cases Disney has made those franchises, once Fox licensed, much bigger and more profitable.
FF is staying with Fox until Iger and co make a move, I don't expect anything to the contrary and you shouldn't either.