I'm no e-bike hater, but anything that make it easier to do something, and do it faster, is going to equal more users and more pressure.
In many areas, that won't matter, because the trail network isn't stressed or crowded. An example would be any trail I've ever ridden at any time around Butte, MT.
In other areas, it will matter, because the trail network doesn't need another single user over what is already present. My backyard trails in Post Canyon during May and June weekends would be an example of this.
Adding another user group -- any new group -- to an existing trail or road or path or whatever system calls for careful evaluation. In some areas, this is being done for e-bikes. In other areas, they are just being lumped in with regular bikes, which may or may not work out fine.