Yeah, maybe people who actually use the option will chime in.
I could easily be wrong, but my assumption is that audiobook listeners are likely to want the opposite (i.e. make the bookmarked pitch persist). I imagine a typical workflow like this:
1) User listens to music with unadjusted pitch
2) User switches to an audiobook – adjusts the pitch for that
3) At some point they may want to listen to music again, or to some other audiobook, so they create a bookmark (which helpfully saves the pitch setting)
4) User listens to music – resets the pitch for that
5) Sometime later, they go back to listening to their audiobook by loading the bookmark, which also restores the pitch...
...so now, the pitch is restored, but only until the device is rebooted, at which point, it is required to once again load a bookmark or manually adjust the pitch after resuming.