Every state has laws governing HOAs that limit what HOAs can do, and usually say that any illegal restriction is void.
That is undoubtedly the case here.
And if a no-gun restriction is legal, then I have no pity for the morons that willing bought with such a restriction. It’s implausible that such a restriction could be newly enacted.
And if it’s not in the original, the homeowners should sue the HOA and demand it be disbanded/nullified/abandoned. Anybody know how to dismantle an hoa?