Please do not mix up this with listings that disappear from a regular group. Can someone here confirm that the later case happens? Suddenly disappearing listings? Then please try to explain us how we can reproduce this issue.
This is not reproducible, I don't think, because they just disappear. As said previously, I have happened to be looking at the screen twice and seen listings there and then gone. I was not doing anything but comparing lists at the time
When you move listing to the trash, I do not see a reason why we should warn the user again.
I think the point here is why do newly started listings move themselves to the trash without the user knowing? (See: Why does leaving the "move original to deleted items" checked after re-listing move newly active items to deleted?).
The search factor is a strange curiosity but I think the fact that the listings are gone in the first place is the important issue.
Every few days I go down my list adding things to existing listings. Every time I find more that are gone and some of the missing have never even been active. I am talking a dozen or more each time, so only about .001% but 12 a couple times a week adds up to thousands a year.
By the way, this was happening long before I lost everything in January. On reconstruction I found literally thousands of items in my inventory that were created years ago then forgotten by GS.