Can an employer really terminate you “at any time” without owing common-law notice?

I saw a recent Ontario Court of Appeal decision involving termination clauses that apparently clarified when wording like “at any time” and “for any reason” can actually be enforceable. It got me wondering how much protection an employee really has when their employment contract contains broad termination language.

If someone signed a contract with a clause like this, should they assume they're limited to the minimum statutory entitlements, or can common-law notice still apply?