I don’t think so - the only time citizenship can be revoked is if it was fraudulently acquired, as far as I know.

We can revoke citizenship if parliament changes the Citizenship Act as part of a secession negotiation. The supreme court will put constitutional guardrails on it but it’s absolutely possible.

The boring answer is that if a province is going to seceed, it will require a negotiated settlement between the said province and Canada, and such a settlement will absolutely contain agreements around what happens with the citizenships of that province’s residents.