The answer to all of this is simple.

OGL1.0(a) is an open source licence and content released under it is open source content including SRD5.1. WOTC have no right under OGL1.0(a)‘a terms to revoke or “de-authorise” the licence or otherwise limit the use of content other than per the terms of the OGL (which is limited to no using WOTC Product Identity without permission and claiming compatibility with DnD).

That’s what the OGL says. That’s what open source means. And that’s literally what WOTC said when they released the OGL.

WOTC’s continued assertion they can deauthorise the OGL, asking people to fill out surveys they won’t read, making empty promises it listen to feedback, claiming it’s all to protect the children, is all rubbish. Complete rubbish. WOTC have no legal right to do any of what they’re trying to do. WOTC know it, and they’re just hoping that if they keep saying the opposite then no one will call them on it. But we are calling them on it.

So, my advice to OP. Make the stuff you want. Make stuff that will help people. Use the OGL. And if WOTC are fing stupid enough to send you a cease and desist, let us know and we’ll do a GoFundMe for the legal costs. Because f companies like WOTC that can’t even just stick to their legal agreements let alone actually give a s*** about anyone or act like they actually exist in a society.