...There's old constitutional law to the contrary on that. It goes back to when there were both a Federal and provincial Temperance Acts. The federal one gave municipalities a 'local option' to prohibit intoxicating liquors locally under the federal law. The federal law drew its constitutional legitimacy from the 'criminal law' head of power granted federally in the constitution. It went through various levels of appeals, but ultimately it was held in 1946 by the Judicial committee of the Privy Council (back when Britain still had the ability to ultimately decide our legal appeals) that it was within the constitutional authority of the federal government to give municipalities the option to ban liquor even in the face of overlapping provincial legislation. While this is pretty old jurisprudence, it has not been overruled, and supports the notion of the federal government being able to empower municipalities to prohibit certain things where it falls within matters that are typically in the federal sphere.
The chain of jurisprudence on this starts with Russell v The Queen (1882), and ends with Ontario (AG) v Canada Temperance Federation (1946). So the constitutional law on this actually may well specifically empower what the feds are considering doing. I've no doubt the federal counsel looking into this are well aware of this possibility, and it's classic constitutional law on division of powers and where federal and provincial authorities crash into each other.
I'm not entering the discussion into whether this is sound policy or not, I'm just offering the caution that the constitutional law on this may not say what you think and expect it does vis a vis the ability of the feds to statutorily empower municipalities.