I agreeThere's no way D23 will not get an Avatar update, Iger will not allow it. That's his thing and he's not going to look like a fool. Same reason there will be SOMETHING Avatar at AK.
And seeing the backlash they got after the last D23, that Staggs had to personally respond to, I doubt there isn't something mentioned for WDW in some way.
I think they learned that showing WDW fans all the cool things all the other parks are getting and they're not isn't the wisest of moves. I am interested at seeing more info on Shanghai and Kitchen Calamity. We'll see what they do for WDW overall, but I'm not expecting anything huge.
I lood for d23 this year yo be very interesting