Which panel did indeed stick to overwhelmingly to SF, despite a mention of Terry Pratchett.
That mention stemmed from a comment on about how stories keep repeating themselves, and a story must have been true once. That notion came up more than once. Like Poul Anderson's ''Goat Song" which is obviously retelling Orpheus even though it is the very hardest of hard SF.
Which is a different topic from having the gods actually show up in science fiction, which is possible. Star Trek did it. Though it does tend to get loosey-goosey about how god-like they are. Things get blurry with sufficiently powerful aliens.
OTOH, there are aliens who have mythologies. Entirely within genre. Still a big problem because the question arises of how alien can they be before they cease to be mythologies? And, still narrower, how alien can they be without our ceasing to care? One mentioned Old Man's War, where aliens thought that a battle on a planet saved the planet -- and one reason it worked was that it was brushed on, not made central.
One panelist discussed her robots' beliefs about their creators. Very schism creating. In a town of 300 robots, you get 280 sects or so. I brought up Freefall and omniquantism. Which robots think very neat, and only causes one in three robots to lock up. And a panelist riffed a bit on the computer that can't handle mythology because it's contradictory. Most real mythologies are contradictory and messy and not straight forward.