They are not appearing in general search. I still see them as related items from listings that show up (or from their demos), but do NOT see them in the merchant area or from my store's webpage or search. They are still in my merchant outbox in-world. There was no communication about items being flagged, de-listed, or anything. I only noticed when I checked a separate MP store (alaskametrostore is the owner avatar, same problem there, at least 3 listings are disappeared), so the problem is likely more widespread than my two stores and impacting other merchants.
This issue has happened to me twice in the past, seems to be a recurring bug. Please restore my missing listings