In this case, this is not a non-issue. If you look at the original github issue, it does a lot of damage, followed by a lot of confusion, followed by a damage-control post that shouldn't have been required if it the original issue was written with more care. It wasn't, because the marketing aspect of Zig was not the focus -- the technical issue was. So it blew up. Hopefully it'll be a lesson learned, but I suspect it isn't. It will take 20 more of such incidents before it sinks in.
As far as it was "announced years ago", I don't see how that matters. The people who are seeing the issue now, and this discussion weren't there to see the announcement years ago.
But I do understand what you're saying. You're point is that the onus is on the the reader to the do their research before overreacting. That's a perfectly fine position. I have a counter opinion which is that the person making the statement / claim / annoucement, simply be understanding of the implication of their statements.
This thing blowing up should not have been a surprise to anyone. Sounds like it would have been to you, so the fact that it blew up is evidence that you would have misjudged. Unless you also agree that the initial message should could have been better worded, in which case, what exactly are you disagreeing with?
LLVM is not and was never going away as a compiler backend, it will just not be the default one and you will be able to compile zig without it (though in practice everyone will for prod releases)
Unrelated to Zig, it's the exact same thing with "WASM can't access the DOM" btw, comes up everytime when WASM is in the news, but is a complete non-issue in practice for anybody actually using WASM, and I'm sure each popular software project has at least one such 'drama issues'.
The 'LLVM divorce' has been announced waaaay ahead (maybe years) of any actual steps to make that happen, for a language ecosystem that's still unstable anyway, and with the promise that a solution will be in place before LLVM is actually kicked out.
Not sure what else could have been done better, and as other have said, this sort of decision making process is much preferable to a committee approach.