This is indeed interesting (and this Q that has been only briefly discussed earlier): So you choose a longer connection at IST but as the shortest possible connection time was still more than 9 hours, the TK hotel desk provided a free transfer hotel? (despite that strictly speaking you didn't qualify as you didn't choose the shortest possible connection time)?

A few years ago I was on the TK shuttle van with a fellow traveller who explained that that he didn't choose the earliest flight to his final destination as he wanted more time to rest/sleep in the hotel. I was quite surprised that he nevertheless was accepted a being eligible for a transfer hotel.

May I ask you, do you speak Turkish/did you communicate with the staff at the TK hotel desk in Turkish?