Nice to see you comparing GC beliefs to a laundry list of bigoted or irrational beliefs.
You could equally say that it is protected in the same way that holding socialist beliefs are. Or being vegan due to animal welfare concerns.
Insulting a trans colleague using transphobic slurs would still be punishable under workplace policy. As would a socialist telling the boss they would be first up against the wall in the revolution. Or a vegan throwing away non-vegan food brought in by colleagues.
You can't however fire the socialist for saying they believe in redistribution of wealth through taxation. Or the vegan for saying they believe farming animals is morally wrong.
Or the feminist for saying biological sex is real and matters in some circumstances.