You brought it up. For the record, I find it an asinine idea to limit current property owner's land in either the commercial or residential districts with these "green" laws (quick everyone, if we all go plant 10 trees the global warming crisis is over).
Still the precedent for laws similar to this is there. IMO worst case scenario, all current property holders should be exempt. If they want to limit new owners of new property, then those people can make an informed decision.
Since he considers homosexual rape harassment, I would think that you are correct.