Everyone's cost will go up, but they won't all go up equally.  Smaller businesses that depend almost exclusively on local employment will see a bigger increase than larger business where much of their workforce will operate in other jurisdictions.

Walmart, as an obvious example, stands to benefit probably more than any other company by this change.  Their local workforce will see some wage increases, but the bulk of their distribution network is located within the U.S. while their suppliers are predominantly in the U.S. or Asia.  They also have global operations so this ~30% change in Ontario wage will be only a minor blip in their global labour costs.  Ohh, and they have almost unlimited capital available to weather any transition periods.

Contrast that to a small local retailer.  Their entire workforce is local.  Their "distribution network" is the back room of the store, all local.  Many of their suppliers are probably local.  And capital?  Not so easy to come by.