No, they (V's) don't work as well as disks in the wet.
Disk brakes do have more stopping power in more varied conditions than V's.
However there is noting intrinsic to electric bikes that demands that they have disks.
I put Shimano Deore LX vbrakes on my ebike when I built it about 18 months ago. They work very well. I have noticed that pads might be wearing more quickly than they would on a regular bike, but that's probably because of the higher speeds and more weight.