Hypothetical: I ignore OGL 1.x

[pemerton]

But implicit permission has to be assumed anyway. You can't comply with the license without copying the text.

Your second sentence is true. But on its own, this wouldn't give parties with no connection to WotC permission to use the licence.

I think they made an express statement the OGL was 'released for general use' - maybe via the Open Gaming Foundation?

Yep, I've seen stuff like that. This is why I doubt that they would have a very strong case for copyright infringement against parties using the OGL v 1.0/1.0a to create their own OGC ecosystems.