I was just looking for the same information and I found this:
Monorail -The monorail is under refurbishment and may have modified service or routes. You should check on the day of travel the best option to use. Alternative transportation options may be available.
Express Beam Overnight Closures- 11:30 PM Sundays - 9:30 AM Mondays, 11:30 PM Mondays - 9:30 AM Tuesdays
Monorail Shutdown- 11:30 AM - 6:00 PM on Tuesdays, Wednesdays and Starting 4/12/2016 on Thursdays
Resort Beam Overnight Closures - 12:00 AM - 8:30 AM Mondays, 12:00 AM - 8:30 AM Tuesdays
http://www.wdwinfo.com/wdwinfo/rehab.htm
What I can't figure out is how long the closures are going to last. Is this temporary, or more of a longer-term thing? I'm trying to plan a trip for November and wondering if it's worth it to stay at a Monorail resort if it's going to be shut down for 6-7 hours a day. We often go back to the resort in the middle of the day, so this would affect us.