I don't know if my town with grandfather them in. The city Council is a bunch of idiots. The animal control person told me she really wouldn't go looking for issues, but if somebody complains then she has to respond.
I have been told by Animal Control that they only enforce the county code, not city codes that don't conform to the county code. If a city code enforcement officer tries to get them to deal with a city code, they will do nothing. If it is a county code issue then they will take action.
Our city did not have a code for chickens and ducks so we were going by the King County code. The idiot city code enforcement officer tried to say that chickens are regulated like dogs and cats (total of three outdoor allowed and unlimited indoor) but that did not hold up in court so he repealed the entire code and rewrote it with a limit of 5 chickens and ducks with no roosters allowed. King County does not have a restriction on roosters so I doubt animal control would do anything if someone did have a rooster but the code enforcement officer would try to bully them into getting rid of it voluntarily. Our neighbors did not have a rooster until the draft of the new code was shared at a city council meeting we attended (but no one else knew about) and she decided to get a rooster before the code changed to have one grandfathered in before the new code went into effect last year just to make sure she protected her rights as a homeowner (since the 1980's).
The issue with the limit of 5 chickens would only be an issue if there were complaints and even then it is technically an animal control issue unless a city has their own animal control officers to enforce the code restrictions. The county animal control officers are busy dealing with real issues and not silly complaints about the number of birds someone has as long as the birds are being properly cared for and not being abused or neglected.
If they see that your birds are well cared for it does not matter how many people complain, they will close the complaints and side with the owner every time. The more false complaints someone makes, the less credible they are so it only makes them look bad when they are caught in their own lies.
I happen to know that even though roosters are not allowed in Seattle, they have some living in a pen outside one of the police stations because they are so often turned loose inside city limits. The only reason they have them penned is to keep coyotes from moving into Seattle to feast on the free chicken dinners in residential neighborhoods.
We put up more privacy fencing to keep nosy neighbors from peering into our yard but, because we fought to keep our birds instead of cowering to bullies, we are protected. I am not sure if our neighbors with more than 5 birds have legal proof but I would testify on their behalf if necessary to keep corrupt city officials, none of whom actually live in our city, from getting away with being bullies.