The Verge’s limits aren’t relevant here as NewsBlur maintains a local copy. At the moment I see articles going back to 16 Mar 2022 which is right about a month, but 521 articles, which is suspiciously close to 500, so I’m wondering if there is some cap at 500 (plus a few new articles, until the cap gets enforced)?
I went digging and found this previous comment which, although dated, does suggest a 500 article cap as well.