Change this hunter to a new type.

I presume that this means that the character retains all previously learned moves of the previous type, right? It wouldn't be much of a progression if the character changed and lost all of their previous abilities. What about further advanced moves? Does the hunter need to level up 5 times in the new playbook to access additional advanced options?

It depends.

Look at the detailed description (p121 of the revised edition), and it should be clear. The hunter keeps those things that they should keep, and discards those that are left behind by this change.

Sometimes a hunter keeps all their moves, sometimes they might keep none. There's no overriding rule here, because it always depends specifically on the experience of the current character and the change they go through.

For the advanced moves, ask yourself if they are starting again from the beginning or if the hunter can still use the experience they have already gained.

I think it's far from "clear", but it is the assumption that's been carried over from AW to other hacks: basically, you negotiate it together.

I could see some games being better off with a much more clear way of doing this, personally. (And some groups, as well.)

You're more or less on your own - you wouldn't get a "by the rules" answer.

Thanks. I guess I had glossed over p121.