I'm confused. What are you seeing in the photos that you believe to be part of the fan disc?
The consensus seems to be that the fan departed in its entirety.
Possibly the hub portion of the disk that attaches to the stub shaft just ahead of the bearing.
There should be a fracture progression there telling which direction it has progressed. Also there is the booster stage drive flange that also would show which directions the separation was taking vs a clean break away.
Meanwhile I'm sure that the pedigree of the Titanium process is being examined in detail at this time to see if there is anything at all that is of concern that might point at other parts of the fleet..
To me it is amazing that the blades themselves did not add to the collateral damage to the aircraft (like Pensacola MD80) and the best news yet. No doubt the Kevlar ballistic protection might have played a significant part.