Your comments

All that said, I do have a workaround of creating a note, moving the search results tree under it, then deleting the search results page itself.
I hope you still add this feature. Let me explain my reason for wanting it:

I often do a google search for something and open a bunch of search results as "child tabs" of the search page. To save memory, I'd like to then delete the search results page itself. But if I do that, all the child tabs will become unorganized. I could just archive the search results page, but then if I forget to delete it, I might later think that it was a search that I still needed to do and had saved for later.

I could make a note and move all the child tabs under it, but that's sort of tedious to do (since I can't select more than one tab at a time).

Ideally, I want to be archive the search results page, then change its name to "search results" or "delete me" or something like that, keep it around for as long as it has child tabs open, and then delete it when I'm finally done.