This part I can answer, it came in part from this Jira (about the status) Loading... and also a discussion linked by Adina above Batch move documents - #2 by vmassol. There’s also this another discussion where a user needs to have some pages moved to a new place, Organizing My Wiki - #4 by mflorea.
It’s different from moving a page and all its children, that part is well covered by the current feature set.
It’s an advanced feature, sure, but I can see the need for it. At least from own experience moving files around in the OS (similar UC) and moving pages around in note taking apps.