Regardless of whether management or the CMs were told exactly what the issues was, there still should have been some mass communication to the guests. It's not hard to leave a voicemail for all rooms/guest cell phones on file for those staying in the tower along the lines of "We are currently experiencing intermittent power issues. We are working on resolving these issues and while we don't currently have an estimated time of restoration, we will keep you posted throughout the day. If you have any concerns, please don't hesitate to contact us via phone or at the front desk."
It isn't a matter of whether they had concrete timelines for when it might be fixed - but rather that they failed in communicating with their guests. It's Florida, in August. I imagine many guests that left prior to 7 a.m. for a full day in the parks returned to get cleaned up to discover their rooms were hot and water was unavailable. A simple phone call could have better prepared them for the situation.
When it became evident that it was a transformer, and as you say the repairs for which are lengthy at the best of times, they should have begun taking action to relocate guests. But based on the reports I've read - many guests weren't aware of the issue or offered a solution until late in the afternoon/into the evening. By that time the power had been out for 8-10 hours. I find it very hard to believe that management wasn't aware that it was a transformer issues with potentially lengthy repair timelines prior to that point.