It is certainly halacha. The Rambam and Shulchan Aruch are citing and paskening a Chazal l’halacha.
If you claim that this is a “Shulchan Aruch that we don’t pasken by anymore” (wow!) you’re going to have to cite gedolei poskim who say such a strong (and strange) thing rather than just your own boich svara. Override a halacha in Shulchan Aruch? It is theoretically possible in a small number of cases, but one needs poskim (of yore) with very big shoes to even contemplate such a possibility, put their halachic reasoning against SA in writing, and have it accepted by the gedolei poskim. On this issue no one of note ever even postulated against the SA. It’s been the normative Jewish practice from Sara Imainu through Chazal through SA and on.
The other question was a silly semantical back and forth that is neither important nor worth wasting keystrokes over.