This is why for teams competing in a North American League the Toronto moniker goes a lot further, like why the Toronto Rock play in Hamilton, or why Raptors 905 aren't called the Mississauga Raptors. Nobody knows where Hamilton is outside of Ontario, more or less. The Wild play in St. Paul but go by Minnesota, but all the Minnesota teams go by that instead of choosing Minneapolis or St. Paul.
Maybe going for a place name gives it some eventual cache, like the San Jose Sharks or Anaheim Ducks, but otherwise you're going to end up in a San Francisco 49ers instead of the Santa Clara 49ers type of situation.
Since the PWHL owns its teams directly and they do not have local owners it's ultimately up to them what they decide to call the team. As there's already a Toronto team it won't be that, but it wouldn't surprise me if Hamilton ended up being called Ontario or Golden Horseshoe instead of Hamilton. It depends on how they view their marketing and media market deliverables.