My guess is that the video displays are typical indoor-rated industrial-grade units enclosed in a custom-built and (supposedly) "water resistant" shells.
If that's the case, and given some of the downpours that I know Florida can produce (because I've been in a few), it wouldn't surprise me at all if the enclosures turned out to be less water-resistant than advertised. Consider that the level of sealing required to truly isolate the units from the Elements would also present some unique problems with keeping the displays cool while running (and plasma displays do get HOT!)
Then again... Given the typical content of the shows, was not having the displays running any great loss? ;-)
Walt Disney World
Tokyo Disney Resort