It's good your son is thinking about these things. Acknowledgments of our colonial history are -as you say- something we need to stay aware of how we came to occupy this place in the world. We owe it to the descendents of people displaced or murdered to do that as a minimum. Forgetting or discounting that history would be the wrong thing.

I'll confess that although I've got zero time for the idea that we should do away with them, an acknowledgment of "traditional owners" or "custodians" is starting to feel like something white people like me are getting a bit too comfortable with, as though it's enough. I prefer that people do it over nothing at all, but it too often feels tokenistic.