Brighterside this is sad news indeed! As yet there is nothing official from QR but the evidence points to it being true. Thr free city tours are no longer visible but the paid tours are, and apparently using the same desk as the free tours used. Note that the number of tours has increased from four to six and that https://discoverqatar.qatarairways.c...transittourtNc says " Transit duration is calculated from the moment the customer disembarks from the aircraft, the customer is responsible for calculating their transit time and to plan for enough time to catch their connecting flight, Discover Qatar will not be responsible for any missed flights resulting from time mismanagement." and the standard "Tours are bookable no less than 90 minutes prior to tour departure subject to availability".
I will add a comment to the Wiki saying it is thought that the free tours have ceased. As yet we have no confirmation that they have ceased.