It seems like you are missing the thrust of the number 5 example. Here goes again. Possible: math professors get together to discuss (er) math. Possible: after much deliberation, math professors announce that 5 is not a number. They’ve recalculated, so to speak.

Do you agree the above are possible? So far we’re just talking people doing things of varying degrees of normalcy and weirdness.

Then enters philosophy: how should I as a person who strives to be cognitively responsible, respond? I assume I can’t just waive it out of hand. A lot of weird stuff has been discovered. Allegedly, a spatially located object could be neither in location A, nor B, nor… That’s a thing right? I mean if that weren’t already a thing and physicists announced it tomorrow, I’d say: what the what. Pass the joint, physicists.

Again: what mathematicians say don’t make it so it not so.