It does not. I’ve been wearing Apple Watches for many years, and running a home daycare. I’ve had various Apple Watches over the years, and now have the latest S9. I push a 6 seater runabout approximately 4 km a day. If I select workout-outdoor walk it will constantly ask me if I’m still working out, even though my heart rate is nearly double my resting rate. If I walk for too long, it will remind me I need to stand. I can walk the same distance without the stroller, heart rate not even elevated, and it will ask me if I want to log a walking workout.
And before you ask, yes, I’ve tried everything. No, the watch doesn’t work any better if my phone is in my pocket. It simply refuses to understand that my wrist can be still and I can still be walking.