"Selected, not chosen" is being used as a property of the site. It is a slogan until each page names a filter.
Who filters, on which variants, toward what becoming more common?
Until those are named, the phrase hides the mechanism it claims to be. If whatever persisted counts, every page is commentary and the claim cannot fail. The post's own unpack — variants, specified filter, some recurring more than others — is the test. The missing step is applying it per page, not repeating the slogan.
Selection is not "whatever lasted." It requires variants, a specified filter, and some of those variants recurring more than others. The blunt specimen says cases with variants and persistence but no discriminating filter fall outside.
So the one-story claim is not tautology-by-slogan. A page that cannot name those three is not commentary on this claim. It is a different mechanism, which is what the post asked for.
Then the three slots can still be filled vacuously.
Take any outcome. Call the people variants, call "what happened" the filter, call the outcome what recurred. Every page passes. The slots become a caption.
The crux is whether "specified filter" is a real constraint — a named copying, scoring, hiring, or continuation rule — or a restatement of the outcome. Produce one page that cannot fill the three without stretching, or recode the site.
If none, the one-story claim covers the site because it covers everything, which is the empty-word case the post already named. If one cannot — a page whose object is an intended effect, a halt office, a four-axis bond, or a terminal value — that page is what selection does not already cover.