The proposal is actually based on a ruling by the Supreme Court (I believe it was a jurisprudence but I'm not sure) regarding equality of human rights.
Now it's up to the senate to either pass it or modify it, and then it will be up to each state's congress to modify its local Constitution to align to it.
Sadly, there's this tactic called "sending it to the freezer" wherein the congress, federal or local, gives little importance to a proposal so that it takes much longer than necessary for the new laws to actually take effect.
I believe this porposal, or a similar one, will happen considering the Supreme Court ruling, so it's just a matter of how long it will take