I do like this quote from whoever the horrendous municipal affairs minister is right now:
Provincial government literally cancelling elections and halving a city council's size = 'getting out of the way'.
For a less flippant comment, short of constitutionally recognizing municipalities' autonomy and limiting provincial governments' powers to unilaterally mess around with them willy-nilly, there should absolutely be some sort of law (like in other countries) which prevents changes to municipal election rules/procedures less than a year before the next scheduled election.