Yep - not only is there no catch right now, but they literally can never add one. The SRD is released under CC-BY-4.0.

The only point of contention is what happens to their new product, One D&D, which will probably retain some nasty payment structure, and almost certainly not be OGL'd. That's fine though - if they build a walled garden around One D&D, they simply won't be able to compete against the open community of 5e.