I can report on the one instance where we had a FP for a ride that was closed within the 60 day window
Great Movie Ride. We had FP for it. In that case, they gave us anytime, any ride FP. And when I say any, I mean ANY. All 4 parks, even FoP. It was also valid for the duration of the trip. Not just the same day. We were then able to book our own FP at HS to give us 3.
Now, I have no idea why they didn't announce that closing outside 60 days, or even remember now how long out it was.
Just that I was shocked at how "open" the FP we got in replacement was. We did not ask for this, it was put in the account automatically. It was not changeable to other guests either (this was in the time where you could change guests on FP)