Correct. But I have no licence from WotC to use their material, as I have not entered into any agreement with them.the license cannot be revoked.
To be more precise about that, I have not taken any steps under section 3 of the OGL v 1.0/1.0a - "3. Offer and Acceptance: By Using the Open Game Content You indicate Your acceptance of the terms of this License."
WotC is under no obligation to continue to make that offer to me. They could withdraw it at any time. To qualify a bit what @kenada posted, they could continue to make the SRD available on their website (so that interested people could read it, make fair use of it, etc) but could declare henceforth that they will not enter into any further licence agreements in respect of it.
That would not change the rights of any existing party to the OGL v 1.0/1.0a, including that party's right to distribute the OGC to further parties (like me). But it would mean that I couldn't enter into a licence agreement directly with WotC. In practical terms, this would be relevant for my Section 15 copyright notice.