Teh Sexy Monkey Queen
It's 7 years unless something is in production.As much as I'd love to see ALL of Marvel's properties in the MCU, I'm pretty okay with Fox keeping the X-Men to themselves. However, I'd really like to see the FF in the MCU. You'd think that Fox would be smart enough to cut their losses with FF and make some kind of deal to trade the FF rights back for more share in X-Men merch or something. But maybe Marvel isn't in a rush to make a deal with Fox to regain the rights to a property that they have pretty much ruined for the public.
I've heard that Fox has seven years to get another FF movie into production before they lose the rights. But it might be longer. Daredevil came out in 2003 and they lost the rights in 2012. So maybe the rights will just revert sometime between 2023-2025. Just in time for Phase 4.