Definitely what I would call "tech speak." :) It is a play on words. AI stands for Artificial Intelligence. Overlords are people with great power and authority. This sentence is actually a header of an article in MIT Technology Review. They are talking about a letter that is addressed to any future AI robot and is written in the way that should affect AI’s future behavior, hence the reason for the header. It is addressed to future robots that may or may not be powerful enough to destroy or wipe out the human race. That is the meaning of the header.