I don't think it's fair to imply that all or even most revivals are a play at tourist money. To assume that tourists even care about half the shows that get revived if they don't get glowing reviews is shortsighted at this point. But I don't think there's anything inherently more tourist-trying about a worthwhile revival than a new musical let alone one based on a known property.
Also, there were... almost no musicals to revive from 1946 until the 70s, and not enough time had passed. And Broadway has been tourist driven since the 80s at least. There are SOOOO many musicals worth doing on broadway written between the 1930s and 2015... whether they've already been done on Broadway or not.
