Most people in Vancouver aren't interested enough in whales to go out and watch them, so unless your friends are nature lovers you might not hear about them unless you ask. I've lived in Vancouver or on Vancouver Island my whole life. Not only is the Strait on the migration path for orcas but there are also resident orcas, who live in the area year-round. I don't know about Stanley Park and False Creek specifically, but for not much more than the cost of the aquarium ticket, you can take your kids on a whale watching tour. Or if you make the habit of taking the ferry, you can just watch out the windows. I've seen a couple pods that way.

There's a reason orcas feature heavily in First Nations art, local sports team mascots, etc here. They're beautiful animals but they're not exotics.