I don't think this is a coincidence, exactly. There was a protester shouting over the recent I/O keynote that Google is "a totalitarian company that builds robots that kill people" in reference to Boston Dynamics. Folks who think that the accusation is overblown have been joking about Google's "killer robot" program, so this easter egg is likely Google poking fun at the allegation.
This is probably a joke with a reference to Terminator, where T1000 and T800 are "killer" robots. So if those robots obey web standards, they should not kill Larry Page or Sergey Brin when they destroy Google.
Not everybody here is technical, and not every technical person necessarily has web development experience.
I've personally worked with some brilliant embedded software developers and compiler writers who likely wouldn't know what a robots.txt file is, because they've focused their skills and talents elsewhere. Despite not knowing what a robots.txt file is, they're still far more technically capable than even the best web developers I've ever encountered.