It is now confirmed on the Sofitel website that the Old Cataract Hotel in Aswan will cease being a Sofitel property on May 1st. Since I have a confirmed 8-day reservation in June, I have written to the hotel to ask if they are becoming an Orient Express property or leaving Accor entirely.
Since it is also now impossible to book the Aswan Movenpick, Pavillon Winter and Luxor Old Winter Palace after April, it would seem that a move away from Accor is actually on the cards.