A couple of teams have touted the benefits of the e-assist road bikes in place of a Derny for training. Same tractable power characteristics as a Derny but in a conventional package, so any team member can pace the rest of the team to work on techniques and strategies.
I can see myself considering an e-assist road bike in 10 years if I want to keep up with the club rides. Just a little boost to keep up on climbs or close a gap so the rest of the group aren't waiting for me to lollygag around. It'd be fun to tag along on the A group rides and not be dropped within 5 miles or guilt-trip the younger guys/gals into thinking they need to wait for the old man at the top of every climb.
As long as it's still mostly pedaling, I see no problem.