That's shrewd on Reid's part and not at all uncommon to try and exploit over-pursuit. Helps keep the D honest.
Yeah, and it was double smart because if you remember in the first half, the announcers were praising how Bosa didn't always "over crash," sometimes he stayed home and it was flustering everything the Chiefs did. So in second half, Pacheco would line up back-right of Mahomes with the option of him running left while Mahomes rolled right. If Bosa crashed, Mahomes would continue to roll right and either run himself (which he did) or throw (which he also did). If Bosa stayed home, he'd give/pitch the ball to Pacheco.
EDIT: I found this... this guy breaks down the 4th and 1 example of the exact play I'm talking about. On SVP's show last night, they showed how the Chiefs used it several times in second half/OT at critical moments, not just one play. Also showed the play were the Chiefs "figured it out" in the first half.