An announcement about closing, new attraction, reopening date, and all of that sort of stuff that typically would be overhyped twelve times over are a catalyst for a reaction to which Disney has no good answer. Waiting means they can wait until it is too late and in the mean time play dumb.
Let's get practical here, though. Very few average guests are going to be upset about Malestrom going, particularly to bring in the current hot Disney movie (which shows no signs of slowing down, in spite of the peanut gallery comments around parts like these). I like Malestrom, but looking at this from a practical/value standpoint, it's going to please many more folks than it won't. The only reason Malestrom gets the lines it does is because it's the only ride in that entire hemisphere of the park aside from Mexico. There really is nothing controversial about it in general, at all.
Ask Robert Iger that. He has so little faith in Disney product overall that he bought non-studio-generated IPs in the belief that THAT was the way to keep the company strong.
A very correct belief, so good on him for that.
Iger isn't a "parks" guy, no question, but the steps he has taken to save Disney's film business, live action in particular, which has been a struggle all the way back to Walt's day, and ensured that it will endure for many, many years to come.
The whole "non-studio-generated" IPs thing is just silliness. "Studios" don't generate anything, creative folks that work for them do. Using as a benchmark who is on payroll at what studio when something was generated seems really silly.
The purchases of Lucasfilm and Marvel were masterstrokes - not only do they fill a huge void Disney had for live action, they can also be exploited in animated franchises and beyond. They are perfect properties to have under the Disney umbrella. I don't see kids settling down to watch John Carter: The Animated Series.
It's certainly a lot more appropriate to Disney than, say, Touchstone pictures was, with Bette Midler mouthing off four-letter words and Julia Robert's selling herself on the streets of LA. And a lot better material than the Disney Channel stuff the other live-action properties seem to be culled from aside from the massive failures of John Carter, Lone Ranger, and even the tepid response Tron Legacy (which I just saw last night and is actually a darn good film).
Disney is simply a studio going after the best material, getting Lucasfilm and Marvel were extremely smart moves for them, and will be paying the bills for decades to come.