@lomapaseo.....Whether the disk moves aft or not, it would still free wheel up in speed at a very rapid rate while remaining centered about the engine centerline. The tendency is for it to seek restraint both upon the remaining drive arm/shaft pieces as well as its still intact blade tips against the outer case structure.
Noting the room between the bearing box and the drive arm, I would disagree that the Turbine remains centered about its shaft, (the engine's centerline). Gas path pressure and gyroscopic forces work against this type of ad hoc stability, IMHO. So I picture the bore portion as contacting the bearing box in a random and chaotic fashion, not conducive to the Turbine's retention, and destructive of its ability to remain in the engine. This impacts the blades against the platform, and they are lost, immediately.
In any case, do you not agree, that from the drawing, the LPT Stator platform makes first contact as the IPT drifts aft?