Yes, there will. Disney is not going to leave any one stranded at a park. Buses usually run for about two hours after official park closing time. One year I had dinner at Rainforest Cafe, when AK closed at 5:00pm (which they frequently do during the off season). It was well after seven when I got out and there were still people in there eating. As I came out toward the buses, there was a CM with a clip board waiting on us. He asked where I was going and sent me to a one of several waiting buses. We sat there for a few minutes and a few more people got on, before we took off. Now that particular bus made several stops at other resorts before finally making it over to POFQ, but it did get me back to my resort. It seemed like everyone on that bus was going to a different resort that night.
We also were one of the last ones out of Epcot one night, when we had a late dinner at Le Cellier. We came out into an almost empty park. That particular time they still had all the regular resort buses running and we were able to get on a bus that went directly to our resort (CSR). This was a little over an hour after official park closing.
Also after the late Hoop de Doo show one night, they had buses right outside, waiting to take people back to their resorts, since the parks were already closed.
So if you get out two hours or less after official park closing, you'll probably find a bus directly back to AK, but if it's more than two hours after park opening, look for a CM, who will make sure he gets you on a bus. In the second instance though, that bus may be making multiple stops, since there won't be many people on it.
