No. OGL can never be revoked. And frankly, the tabletop side of D&D is a tiny blip on the radar for Hasbro now. It would be the same with Disney.
Yep. Besides, even if they
did notice the OGL decide to "do something about it", there are quicker, easier, and more effective ways to do so.
The truth is that there are exactly 2 OGL publishers of any consequence to Disney/Hasbro/WotC: Paizo (with Pathfinder - rivalling D&D), and Green Ronin (with M&M/DC Superheroes - rivalling Marvel). Everyone else is almost completely irrelevant
even in terms of the RPG market.
So if they really want to (effectively) kill the OGL, they just need to add two more acquisitions. And while the owners might not want to sell, I daresay they could be moved by a sufficiently large number of zeroes on the cheque.
What is more interesting to me is that FFG and MWP could find the rug pulled out from under them in terms of their rights to do a SW or Marvel RPG. WotC had those rights in the past and let them lapse because the cost benefit wasn't there, but getting them back for free would have to be pretty attractive to the gaming group at WotC I would think. Especially with new SW and Marvel movies on the horizon.
The license probably ties up the rights for a number of years, most likely with clauses specifying a number of products (and some sort of 'approval' clause), so it's unlikely that Disney could just yank them back. However, I suppose there's a possibility of buying out the license.
Of course, all of this assumes that Disney even notice D&D or RPGs, which seems unlikely. And, frankly, I rather hope that they don't, because my gut feeling is that the likely outcome of that is not "WotC get lots more game licenses to play with", but rather "D&D isn't profitable enough, so they cancel it."