Past practice has been for the diagram to start as an HST on changeover day then swap to an Azuma in London so I'd imagine that it will be a HST on Monday morning for the last time then go out of service at Kings Cross.
The 0752 on Monday is booked to be a HST.
The 0952 and 1452 on Monday are also showing up on the planner as HSTs, so assuming this is the case on Monday then the 1452 departure will be the final one of an LNER HST from Aberdeen (other than the farewell tour, of course).