I have read lately a bit about e-bikes and the Valley Trail. I should state that I do not own or ride an e-bike (not yet anyway) but I would like to offer my opinion on this heated topic.
The gist of what I have to say is that this is about the rider, and not the bike. Whistler is full of respectful and considerate people, some of whom ride e-bikes, some of whom ride other forms of wheeled transportation. A mountain bike is quite capable of riding too fast, just as an e-bike is—and often they do go faster than they should. (I know this because I have been guilty of this on occasion on my leg-powered bike).
I do not know what the rules should be, but the signs on the trail say “share the trail.” We need to respect each other—regardless of our mode of transportation.