I will have to go looking, but somewhere I saw a very learned and well documented article that pointed out the the "wassail" custom (like quite a few others) does not appear to have a history that extends back before the early 1800's. Evidently there were quite a few people who practically made a profession out of thinking up and diseminating "traditional" rituals of all kinds, which society of those days took up in fads...

anyway -- in my opinion 150 plus years is still enough to make something "traditional" so what the heck.