It's Archive.org being provided URL telemetry for archiving public sites they have not yet found through traditional means (crawling or users submitting requests through the Wayback Save page) by a Cloudflare product.

The next step would be for Cloudflare to point to Archive.org Wayback links when an origin isn't available (similar to browser extensions that point to Archive.org when sites 404 or are down, but in Cloudflare's core).

Cool stuff. Thanks Cloudflare folks.