Not necessarily.
Apostate: One who has abandoned one's religious faith, a political party, one's principles, or a cause.
I referred to them as "Apostate Jews" to indicate both that they had abandoned their faith, and that the faith they abandoned was Judaism. I don't know that they had enough time to formulate a new religion while while Moses was on his little side trip, although the Bible does record that they were using the trappings of other pagan religions.
In any event, you have already very ably showed me where I was mistaken in my understanding of Jewish law with regards to destroying other faith's places of worship.
(So why don't the Israelis simply obliterate the el asqa mosque? It's not like the mohammad-damned will hate them any more than they already do!)