MCL 123.1102 states that a municipality shall not enact or enforce any ordinance more restrictive than State Law.
Some of your answer is right in front of you. I for one would not waste time and resources to change an ordinance...unless they try to enforce it.
Also, in my opinion; I don't believe any law or ordinance would be "grandfathered" unless provisions for same were written into the new law. Much like the old liquor laws were "incorporated" into the new re-written version.
BTW: HAPPY BIRTHDAY YOOPERLADY....again.