I know that these josekis are definitely before AI (and even before PC): they were published in 1966.
So I wondered: does this - playing tenuki in the middle of a joseki and therefore allowing the opponent the advantage of playing two successive moves locally - still happen nowadays?
Yes, the most prominent example is ignoring an approach to a 4-4.
Playing tenuki in joseki is one of the notable changes post AI. There are many new patterns with tenuki but this one stands out in my memory. Either White tenukis after Q14 or Black tenukis after any of the pincers at 1, 2, or 3.
The change in the 3-3 invasion is also simply a tenuki joseki now.