It will be set in modern times.
Bending will become extinct.
Katara rises from the grave riding a wave while eating seal-jerky
The “Big Bad” will be an AI.
Things that may happen but probably not:
Political intrigue, specifically centered around Ba Sing Se.
The protagonist will be a no-nothing street urchin with a pension for pick-pocket.
The “Big Bad” will be someone’s mom (probably will be someone’s dad).
The mentor is basically Yoda/Boomi.
Edit to add: The avatar’s spirt animal is a turtle-bear or a badger-mole.
Interesting take XD - I love the OG series and started getting annoyed with the second partway though because of the direction it started to take, but the third one does interest me, so I’m excited. I don’t think there would be… Hmm… twin avatars would be cool, but I don’t think it’d happen XD.
I do hope that they make it more adventure-themed than Korra. With the enmeshment of the spirit world and regular world there’s so much more to explore, plus I’d love to see the state of other nations. I was very “ish” about Korra, despite it having some cool ideas and elements (no pun intended), and I think that had a lot to do with the world feeling unexplored save for a couple key places (though, admittedly, I only ever finished the series once when it first came out, so possibly I’m remembering wrong? Never really liked it. First season was good, but second-season was a drop-off point for me. Too much eye-rolling romance plots for me to enjoy. Hope they deviate away from that, tbh.)