This. It is standard practice at resort hotels all across the world to notify booked guests of closures, rehabs and other onsite maintenance/construction/etc. that is out of the ordinary and could negatively effect their stay. This way it's not an unpleasant surprise and those to whom it does matter significantly can make changes in their trips or accommodations, if desired.
It's not so much that it's happening, but how Disney has handled it. Ever since construction began at the Grand, no Grand guests, from what I know, have been officially notified (i.e. a call from Disney) of the construction at booking. You wouldn't know anything about it from Disney's own promotion marketing, website or available public information about their resorts.
I know we weren't. I read about it here and only after I called to find the impact it would have during our stay, did I get any kind of information from Disney ... And then only after repeated contacts (several emails to various addresses, including IPO, and two phone calls).
This was also towards the beginning of the reduced monorail hours and, frankly, Disney handled it dismally, transportation-wise, as well as the impact of frequent unplanned shut downs of the lines, which were a daily occurance. Without the monorail, the transportation options at the Grand, including self-parking, are pretty bad ... The equivalent, or worse, of most Values--for five times (at least) the price.
At least at the Polynesian you have walkability to the TTC for additional bus and ferry access and, from the Contemporary, the walkway to the Magic Kingdom, which at least ameliorates some of the inconvenience. At the Grand the monorail or resort bus system are your only options. And as someone who has waited upwards of 30 minutes every single time we tried to take a bus to/from the Grand, which shares buses with the Poly and Contemporary, it's not terribly exclusive or luxurious ... Which, accurate or not, is definitely the way Disney sells the Grand Floridian.
I realize the information is only anecdotal but we were also stuck on several rides, and saw several others shut down unexpectedly at times we wanted to use them; something that had never happened on any previous trip I'd taken to either Disney World or Land. It seems like routine maintenance may no longer a priority (i.e. it's cheaper to do less).