In T380062#10328165, @Pppery wrote:

Note that this seems to be the Beta feature being disabled, not the maintenance script that moves to subpages which uses different code.

Indeed, most moves for T332022: [Epic] Undeploying StructuredDiscussions (Flow) will be maintenance-scripted.
Manual moves are limited. Most of these moves are done by the actual user of a page.
@LD, would it be acceptable to encourage users do the manual cleaning themselves, which will include re-organizing their pages the way they want, instead of fixing this issue (which has a cost larger than the need)?