For dance, we have:
1. Papadakis/Cizeron
2. Sinitsina/Katsalapov
3. Hubbell/Donohue
—
4. Stepanova/Bukin
5. Weaver/Poje
6. Chock/Bates
The top three is fairly easy, since they should get a host spot. I agree with
Colonel Green that P/C will want NHK as their 2nd event. I think S/K will want SC over doing CoC to avoid back to back events with a 5 hour time difference, so we would have P/C with IdF and NHK, S/K with SC and CoR, and H/D with SA and CoC. If S/K do want to avoid SC like
Ice Dance suggested, then doing SA and SC back to back would be fine for H/D, since they are on the same coast.
The next three are a bit harder. W/P will get SC, but I'm not sure if the other two will get their home events. The US fed doesn't need to save host spots for anyone, especially with Manta/Johnson not competing, so it's all about whether or not they want their top two to go up against each other. The Russian fed does have several teams who they might want to give host spots to (Shevchenko/Eremenko, Khudaiberdieva/Nazarov, Popova/Mozgov, Konkina/Drozd, etc.). I'm not really sure which way this will go. If I really had to guess, I'd say neither will be at home, but I'm not at all confident about that. If that is the case, it could be something like this:
SA: H/D, S/B
SC: S/K, W/P
IdF: P/C, C/B
CoC: H/D, S/B
CoR: S/K, C/B
NHK: P/C, W/P
For host picks:
SA depends on whether C/B end up here as well as H/D. If they don't, I think there's a good chance H/B are, with the 3rd spot going to one of McNamara/Carpenter or Carreira/Ponomarenko. I don't expect them to leave a spot TBD here, since there isn't really a team outside the top 5 from Nationals (who should get 2 spots either way) that I think would get it.
For SC, W/P will be here and I think G/P will not. I expect Lajoie/Lagha to get one of the other two spots. The third could be Fournier Beaudry/Sorensen. If not FB/S, then likely either Soucisse/Firus or Sales/Wamsteeker. There are a could junior teams moving up they could consider, but I don't think it's that likely. Like SA, I think this probably won't be left TBD.
For IdF, P/C will be there of course, and I think Galyavieva/Thauron will be too. For the last spot, they could either go with Lauriault/Le Gac, or save it for a team who wouldn't get any spots otherwise, like Wagret/Souquet or Lopareva/Brissaud.
For CoC, I'm expecting the three teams from 4CCs will all get a spot, so Wang/Liu, Chen/Sun and Ning/Wang.
For CoR, other than S/K I'm really not sure what they'll do. They could have S/B there, or if they aren't Z/G could be. Or neither of them. And as I mentioned earlier, there are several candidates for the host spots here. They have two JW medalists moving up to seniors, with Shevchenko/Eremenko guaranteed one spot via WS and Khudaiberdieva/Nazarov guaranteed nothing. They have the 4th place team from Nationals Popova/Mozgov guaranteed nothing. They have teams like Evdokimova/Bazin and Skoptcova Aleshin guaranteed one spot, but both near the bottom of the top 24 SB (20/22), so not sure to get two without help. They have a new team in Konkina/Drozd who looked at least somewhat promising in their debut, and will have been together for longer by then (and of course he's very talented). And there's always Morozov/Bagin

. I'm not even mentioning Shpilevaya/Smirnov, because if they chose M/B over them last year, they likely won't get a spot with so many teams in the mix.
For NHK, it should be just Komatsubara/Koleto.