I cannot speak for the 14-50 but I have a Tesla Wall Connector installed outdoors, as do many other owners and destination charging locations. Some people put roofs over them to help keep rain/snow off them, and that does seem like a good idea, but I have not done that. (It is, however, a good idea to try to keep snow out of the inside of the cable connector and the charge port, because it can interfere with proper seating of the connector in the charge port.)
My car often charges just fine when it is snowing or raining.
Having said that, my WC failed after about 2 years and was replaced by Tesla. I do not know if moisture was a factor, but the electricians who replaced it did not suggest covering the new one.