I wouldn’t bet on it being 5 years before they do anything with the X-Men. I would bet on it being a while though. Feige stating that they started working on a 5 year plan doesn’t mean that it was all set in stone or that the X-Men (or Mutants) can’t show up for at least 5 years. But having started working on that before the return of these characters became official means that they would be used later rather than sooner. Based on their past examples, their plans are more fluid the further out they go. I do agree that they should take their time and not rush things. But I do expect that they will start doing “something” with Mutants within the next maybe 2-3 years. If they do plan on integrating the X-Men into the prime MCU, they have to use some sort of creative slant on the material to explain why society hasn’t been aware of them. If so, I wouldn’t be surprised if they lay the groundwork for something like that over a few unrelated MCU movies. But I’d hope the see Marvel’s Fantastic Four and Doom arrive in the MCU before the next iteration of the X-Men gets going.