Maybe Apple will have a trade-in program to recapture some of that gold. Offer a reasonable amount off the next version upon surrendering your old watch and that takes the sting out of the upgrade. Gold is gold. They're going to need to buy gold for the new cases from somewhere anyway.
They pretty much have to do that. There are plenty of places one can sell gold jewelry for the gold value, so no worries about losing the value of the gold. It just makes too much sense for Apple to give you that value as trade-in credit for them not to do so.