The stock stuff should be fine...if radio replaced with a non marine one....not so sure. I had my old 2012 JKU get drenched several time (leather seats) and all was well, except for water coming down on my head every time I turned!
Been caught out in the rain a couple times in my TJ and all works as it should .....Had a Meyers Manx style beach buggy and got caught in an absolute deluge got so bad I had to wear sunglasses so the rain wouldn't hurt my eyes and I needed wipers on the inside of the window haha...but all electrics worked fine including the aftermarket radio
Fresh water doesn't usually cause permanent problems for low-voltage electronics. Even the typical poly cone speaker is fine if it gets wet, just don't use paper (which is rare) cone speakers in a Jeep. If something gets wet from clean fresh water and starts misbehaving, it normally starts working again once it dries out. Salt water is a different story... salt water will wreak havoc with electronics.... low voltage or high voltage.