Maybe - likely we’ll trade-off the added build/test/storage cost of maintaining each variant - so you might not see amd64v4, but possibly amd64v5 depending on how impactful they turn out to be.

The same will apply to different arm64 or riscv64 variants.

Probably not v4 unless AVX512 becomes more ubiquitous than it looks like it will. But yeah, I don't expect this to be the only variant ever.