I think they want to price discriminate: the costs from AXFR should be minimal, as it is an old technology, very optimized and low bandwidth. However, cloudfla

I think they want to price discriminate: the costs from AXFR should be minimal, as it is an old technology, very optimized and low bandwidth. However, cloudflare decision turns cloudflare "free" offering into a free SPOF. They should extend this offer to their free users, who could then use the secondary DNS that most hosts/domain name sellers provide for free to the IP that is proxified by cloudflare. It could even be limited to the case of proxy or cloudflare DNS failure, so that cloudflare could still price discriminate (make AXFR fail, unless cloudflare is down, like a dead man's switch)