Seeing as accepting the license and using open content licensed under that license requires that you copy that license, you actually can't lose copyright as long as the agreement is in place.
I think you may have lost track of the scenario under discussion? When you talk about "accepting the licence" I assume you mean entering into a licence agreement with WotC; but I was talking about a scenario in which someone with no licensing relationship to WotC nevertheless uses the OGL to license their own work.
Consider four parties: W(otC), X, Y and Z.
W publishes a piece of text, titled the OGL v 1.0a, and asserts its copyright in that text.
X publishes a document and decides to license it to Y. X wants the license to be an open license with a viral character, and so decides to use the terms set out in the text published by W. At this point, X is copying text in which W enjoys the copyright. X is also requiring Y to (i) reproduce that text in its licensed works, and (ii) require that further downstream licensees, like (say) Z, to do the same.
Where do X, Y and Z get any permission to reproduce W's copyrighted text? My view is that it must be an implicit permission that results from W having promulgated the text and encouraged others party to use it to create licenses in exactly the way that X has done and that Y may do in the future.
But what if W now makes it clear that they are revoking any such permission? Then X and Y would have to rely on some sort of estoppel or waiver argument, which is not out of the question but (I think) is more complex.
There is also the possibility that X, Y and Z don't need permission because they are making fair use of W's text; but I don't know if US copyright law considers this sort of use as fair use.
Note that the problem I've just outlined does not arise for parties to the OGL with WotC, because in that case WotC is clearly conferring permission to reproduce the copyrighted text because that's is exactly what they require via the terms of their licence (especially sections 2 and 4). I believe that Evil Hat mention WotC's SRD in their own section 15 notice when they offer Fate under the OGL v 1.0a (though I'm not sure - I'm going on what others have posted) and if they do so, it seems to me that this may be why they do so.
If the license is revoked, so is the need to copy it, which could mean I no longer have permission to do so.
Again, you seem to be talking about
WotC purporting to revoke the existing licensing agreements to which it is party, whereas my post to which you replied was an attempt to analyse the situation of publishers who are not party to any licensing agreement with WotC but who want to license their own work via an open licence that has the terms of the OGL v 1.0/1.0a.
"You may use any authorized version of this License to copy, modify and distribute any Open Game Content originally distributed under any version of this License" means it's up at the discretion of the licensee, not the contributor. I can't force a licensee to use any particular version of the license, they can choose which one they want.
The way to "force" someone to use one or other version of the licence is to introduce such a requirement into your licensing agreement. This is what I assume that WotC will do with its OGL v 1.1, and what it did do with one iteration of the GSL - thus obliging parties to the new licence to renounce their rights under the old one.
But again this does not bear upon the scenario I was discussing in my post. I was pointing out that in the sort of situation I've spelled out above, even though X, Y and Z have no contractual relationship with W, they have agreed as between themselves (via the terms of their licences, which are the terms of the OGL) to permit W to vary the terms on which they may license to one another (if W were to exercise its power under section 9 of the licence between X, Y and Z).
Honestly, if it was just "5.5 is OGL v1.1 and no other licenses", and they leave OGL v1.0a (and all "not-5.5" games) alone, pretty much everyone will be pretty chill.
The potential damage if they somehow revoke OGL v1.0a is very, very scary, so people are decidedly not chill.
It's not clear that WotC is doing anything other than the first thing you describe. See the first post upthread by
@bmcdaniel.
I think you are running together different legal interpretations of the notion of "revoking" the OGL v 1.0a - namely, (i) ceasing to offer licences on those terms, (ii) purporting to remove from existing licensees the power to create new sub-licences of WotC's existing OGC, and (iii) purporting to unilaterally revoke all existing agreements under the OGL v 1.0a.
The first thing WotC can obviously do, and that's been obvious for 20 years. I believe I was the first person to post about the possibility on ENworld, 10+years ago.
The third thing is something that I, and various other legally trained posters (but not all of them) think can't be done. See eg that first post by bmcdaniel, or my other posts, or
@S'mon's post.
The second thing is the least certain -
@S'mon and I doubt that WotC can do that, because it is contractually precluded from doing so. bmcdaniel described it as not being clear.
