I've known about this since November since I have an inside source, but I couldn't talk about it. The Madison only being open from the state line down is a surprise and a bummer. The fishing would be much better (at least in April-May) up close to the confluence. I'm going to have to alter the "winter fishing in Yellowstone" page I've been working on...
The friend I have on the planning committee says the Gallatin and Firehole will probably join the party in 2026, and possibly the Gibbon as well. Cutthroat waters are unlikely to open early, though they could open the Yellowstone in the canyons without hurting anything. Lamar System not so much...
The Gardner River is going to be one of the best wade fisheries in the Rockies from November through April moving forward, since it never gets under the high 40s below Boiling River. The late winter rainbow fishing will be as good as the fall brown fishing, and there ought to be heavy Mother's Day Caddis and maybe Skwalas in April.