(A) How is a CTO responsible for deployments? CTO oversees the development evolving the company’s strategic technical direction so that's its beneficial for a business. Twitter is not your typical YC startup. Large companies' CTOs should not care about things like "this could DDOS us". These are the responsibilities of SDEs.
(B) No, but I just googled it and I can't see how the term applies here. In my opinion, it doesn't.