No idea about Apple Watch, but wife, definitely. My wife noticed it. (She's also a doctor, but anyone can identify the sound of choking and gasping, which is what it sounds like.)

I can't give medical advice, but: Record yourself on your phone overnight and listen back. If you hear loud snoring with gaps or pauses in between, and especially any sort of choking, gasping, or coughing sound, and you don't remember doing it... definitely look into it further.