So reading the article you’re right, it’s technically anycast. But only at the /24 level to work around BGP limitations. An individual /32 has a specific datacenter (so basically unicast). In a hypothetical world where BGP could route /32s it wouldn’t be anycast.

I wasn’t precise, but what I meant was more akin to a single IP shared by multiple datacenters in different regions (from a BGP perspective), which I don’t think Cloudflare has. This is general parallel of ingress unicast as well, a single IP that can be routed to multiple destinations (even if on the BGP level, the entire aggregate is anycast).

It would also not explain the OP, because they are seeing the same source IP, but from many (presumably) different source locations whereas with the Cloudflare scheme each location would have a different source IP.