This could be a case of selective enforcement, a deliberate attempt to retaliate against the man for his previous speech, which would be illegal under federal law (see Gonzales v. Trevino).
It’s also possible that this is not a new thing and the municipality in question just regulates city business very strictly. This is bad in its own right, it grants too much power to the state which can be abused, but would not be a free speech question.
There's unreasonable discrimination because the public comment period is only used for speech which disagrees with the government.