Why did Mokubai unilaterally close

https://superuser.com/q/1540916/926483 (why Word highlights "Numbering" and not "Multi-level List")

as a duplicate of

https://superuser.com/q/1540918/926483 (why Word can't apply either to an un-numbered paragraphs)?

Doubtless they are not duplicates. In the first, Word applies a numbered list to text, but the wrong one. You get a numbered list in the end.

In the second, Word isn't applying any numbered list. You get no numbered list in the end.