The main reason that Cloudflare wouldn't share this info is to prevent competitors like Akamai to operate a CDN as good as them. It looks more like sabotaging competition than increasing privacy.
Exactly. Their own answers in the threads over here at HN are basically admitting as much — they claim to be working on solutions alternative to ECS, because Google and some others have more PoPs than Cloudflare does. They're obviously using this as a competitive advantage to slow down competing CDNs. And noone's talking about!