It shouldn't get stuck, but it may take a several minutes for the autopricing to finish. This is sort of the reality of autopricing thousands of items, it can take some time. You can safely leave the page once you click autopricing; you don't have to stay on the page while it does its thing. It will send you a sidebar event when it is done.

(The previous autopricer issue was that it would crash completely from trying to price everything as fast as possible. So, after the fix, it will at least not get stuck anymore, and finish autopricing eventually. It goes as fast as it can without crashing. It seems like yours finished in under an hour. Unfortunately, when it is automatically pricing this many items, there is not much more we can do to make it faster without crashing it.)