It's worth noting, even if the pantheon is demonstrably real, it doesn't necessarily have to suggest that they get the religion they want. Everyone may agree that the gods are real and who they are and what they do, but that doesn't mean they have the same attitude about it. It seems likely to me that people might love or hate them, embrace them or avoid them, seek a "united pantheon" or try to pit god against god. Philosophies would still emerge that are religious in nature but seek to fill in any intellectual or behavioral gaps the gods might have left. Take a look at Tao or Buddhist concepts, for instance, which many local cultures have adopted around their pantheons.