They did. Repeatedly. You see it mentioned in the few emails the OP chose to share. But they also didn't share the other communication they had over the month long discussion they had with cloudflare.

> BYOIP also costs nothing to produce.

That's not really accurate. Cloudflare is entirely built around one big unified anycast network. If you want to provision an entirely separate network that maintains all the same features they are using from the main cloudflare network, that's going to require provisioning a lot of cpu time and routing table slots at a lot of different sites plus whatever admin and engineer overhead comes from maintaining this quarantined service.