That's not true.

Okay, then you'll need to explain the annual emails I've gotten saying "Your application to the Wikipedia Library has been approved" after I apparently tripped and fell and filled out a manual form applying to the library every year.

It doesn't seem selective once you meet the four aforementioned criteria, but you do need to manually apply.

The idea you're talking about, meanwhile, is nonsensical and doesn't address basically anything about the massive structural problems blacklisting archive.today imposes. I wholly support expanding out the Wikipedia Library, but even this pie-in-the-sky version of it falls too far short of what archive.today provides – and that's just going forward in an ideal world where you can snap your fingers and make this fantasyland WPL happen as soon as archive.today is blacklisted.

The "backcatalogue", so to speak, is what's going to be the most catastrophic part of this by far. I spent years where my main focus was just on bringing dead sources back to life; I don't know the full extent of how bad this is, but I know for damn sure what you've suggested (which won't ever happen) undoes barely a fraction of the damage.