I think this also is happening due to limited capacity and tourism being down and such. What I mean is, they may have wanted to do this for awhile for all we know, but there's no perfect time to close one of the mountains for an extended period of time at the busiest park in the world. With travel and attendance being low right now, this is the perfect time to get something like this done and it won't really effect daily ops much.
While we're at it, lets fix Space Mountain while the crowds are still low.