Okay, so I watched a Screen Junkies video where they speculated when the Fox-held properties would appear in the MCU. The guy they inexplicably call Billy Business said he thought it would take
8 years for that to happen. 2025 was his guess.
I think that's ludicrous. It will take at least 3-4 years to get an FF/X-Men franchise up and running, but the characters will appear in other films before then, imo. Feige isn't about to let those heroes lie fallow for so long. That would be potential wasted.