WotC only has to worry about whether someone tries to compete with those core book sales, which is why we won't see an OGL for 5E because it would be a lot harder to pull that off using the old license.
Now THIS makes sense. Expect Adventures, Modules, Splats, etc from companies, but not Pathfinder 2 or the other core systems. Makes a little more sense, since that would actually help move their own product push forward.