I think you basically got it. I hadn’t heard about the guided packages.
After October 15th there is no (legal) camping in Baxter State Park. But, Katahdin can still be climbed. They still use the Class 1 through 4 system. But here’s the problem: if you enter the Park around Abol Campground you have a 15 mile jaunt just to get on top of Katahdin. Then you have to get back down - with no camping inside the park. About the only way to do it is to do the climb and come down, hiking past the main entrance gate. There you would have arranged for someone or a cab to pick you up. That’s assuming the road is passable.
jaws