no, not really

i ride with a regular summer tire in the rain a lot and never experienced issues, the traction is reduced, yes, so you probably shouldn’t try to do pedal-scraping turns at high speeds, but other than that you’re fine

from the outside perspective i guess it would seem that an EUC is very slippery and unstable, and to some degree that is true, but with a proper tire you can ride on any surface just fine, for example there are winter tires with a lot of threading and spikes that allow you to ride on basically pure ice without any issues)