Can someone explain more about what happened here?
After an earlier history of legal action against 3rd party publishers (TSR essentially bullying competitors to bankruptcy)[0], D&D's core rules were released under a license called the "Open Gaming License", which includes a license update provision reading "Wizards or its designated Agents may publish updated versions of this License. You may use any authorized version of this License to copy, modify and distribute…
That's fine by me, they can do what they want with One D&D licensing and people can make their own decisions on how they react to it going forward.
But trying to pull the rug out from the existing OGL for current and previous editions was a real dick move.