Like there’s going to be an army of people paying thousands of dollars for a silent electric bike to get into the back country
You can convert most any bike into an ebike now. The equipment is readily available from many sources, including ebay. The local bike shop will convert my fat tire bike and install a 750 watt motor for around $1000.00--parts and labor. So, you don't have to pay "thousands" for an ebike today.
In Oregon its 1000w with no throttle (pedal assist) , in Idaho is 500w with no throttle (pedal assist). On federal forest lands is 750w with no throttle (pedal assist) unless otherwise noted.
Pedal assist as a reference/limiter is archaic and from the time of the "first" ebikes. That was the lure in our locale that prompted allowing them in the first place (and why we now have a problem where I hunt). They were only supposed to "help out" on difficult terrain (thus, pedal assist), not just let you cruise with no effort. The current crop of "throttle-less" models are near continuous on anyway, as you barely have to pedal to make the motor kick in. Then the owners mod the controls to have a quick detach throttle they can "pocket" if Johnny law shows up.