keybase.io is another centralized third party which, like Signal, we should be trying to move away from rather than becoming more dependent on. By relying on the DNS (which is already trusted to make email, keybase.io, and Signal work), every service provider can be in control of the keys they are publishing.

Also, keybase.io, being centralized, isn't as auditable as the DNS, but admittedly there is work being done on both DNSSEC transparency:

http://blog.huque.com/2014/07/dnssec-key-transparency.html

and keybase.io publishing to the bitcoin blockchain:

https://keybase.io/docs/server_security/merkle_root_in_bitco...