Provincial Park Authorities do not have the right to specify who can use the water .Under federal navigable waters regulations they can apply to close a waterway to power boats, or horsepower , or speed restrictions etc. If they are successful in getting a power boat restriction its all powerboats including their own and any commercial operators.
Its a fairly detailed process that requires opportunity for public and other inputs and must be adequately advertised.

Provincial Parks are high handed in several waterway restrictions but to my knowledge have not been tested in court.

However federal waterways such as Malign lake can be designated as anything they want to allow. Hence commercial but no private.