Not in Canada. My Post Graduate Work Visa allowed me to work wherever. Or not work at all. The US has so many variations of slavery-lite it is genuinely disturbing.
The US has something called OPT, which is essentially the same thing - you can work for any employer or for no employer, anywhere in the US. OPT lasts for a year, which is longer than the shortest time you could be authorized for under Canada’s program (8 months) but shorter than the longest time (three years).