So, here's the thing: X-Men: Apocalypse didn't just bomb at the box office. With a domestic opening weekend gross of just $65 million, it sure didn't prosper - and the fact that after two weekends it still hasn't caught up to Deadpool's opening weekend of $132 million is surely concerning for Fox - but it wasn't an unmitigated disaster. After all, with a $302 million international gross (and counting), the film can likely afford a lackluster domestic performance and still make plenty of money.
The problem for Fox, however, is that while X-Men: Apocalypse isn't a failure, it certainly isn't all that much of a success - looking likely to eventually clock in at a far lower total than its predecessor X-Men: Days of Future Past or this year's Deadpool (Apocalypse's current worldwide total is $424 million, leaving it more than $300 million short of both of its forerunners' final grosses).
With that in mind, then here's the big, tough question for Fox:
Have X-Men: Apocalypse's Box Office Struggles Made It More Likely That The Fantastic Four Will Head Back To Marvel?
More specifically, with last year's The Fantastic Four having tanked fairly catastrophically (making only $56 million domestically, and $167 million in total), will the relative under-performance of the latest installment in the main X-Men franchise prompt Fox to reconsider either selling the rights to the (as-of-right-now deeply unprofitable) Fantastic Four to Marvel Studios? Or, failing that, will X-Men: Apocalypse's stumble make a similar 'rights sharing' deal with Marvel to the one Sony signed up for with Spider-Man sound a lot more appealing?
The logic behind that thought is essentially this: With the core X-Men movies seemingly haven given over the title of 'lead Fox superhero franchise' to Deadpool, it may well no longer make sense for Fox to persist with the production of poorly received Fantastic Four movies simply to maintain the company's rights to make them (there's essentially an inaction clause in the contract - if Fox doesn't make a movie using the characters for a certain number of years, then the rights revert to Marvel). X-Men: Apocalypse, after all, will surely turn a profit - but not a large enough one to support failures elsewhere.
Why Would Fox Want To Let The Fantastic Four Return To Marvel, Though?
Well, there are three key reasons here, all of them financial.
1) With riskier box office prospects like The New Mutants, X-Force and Gambit likely hitting theaters over the next few years - and the core X-Men franchise no longer a guaranteed money spinner - Fox may not have room in the budget for another potentially under-performing Fantastic Four movie.
2) If that's the case, then there's a risk of the property going unused for years, and Fox eventually watching as the rights revert to Marvel for nothing. Plus...
3) Sony is set to make a whole lot of money out of its 'shared rights' deal with Marvel Studios, being set to keep all of the profits from Spidey's Marvel-affiliated solo movie, which looks likely to make 'MCU money'.
Making A Deal With Marvel Could Take Away Pretty Much All Of Fox's Financial Risk
Y'see, either Fox could sell the rights to Marvel outright, thus recouping the lost income from last year's The Fantastic Four, likely with some left over to invest in future projects, or it could make a Sony-like deal, and allow Marvel Studios to turn the property into something immensely profitable (throw an Iron Man cameo in there, and the movie's golden). Either way, there'd be money to be made, with far less risk than going it alone with a sequel.
Fox producer (and The Fantastic Four writer) Simon Kinberg may, after all, have recently insisted that the team is very much a part of Fox's plans - but there's nothing to stop the company from making those plans a little more Marvel Studios-associated. In fact, with Marvel seemingly taking some small steps to more away from the vertically integrated, executive-led modern 'studio system' its success was largely built on, there may never have been a better time to initiate a collaborative project like a co-owned Fantastic Four movie.
Or, y'know, Fox might just make another FF movie all by itself, make millions of dollars in profit, and ensure that all of this speculation has been for absolutely nothing.