It's no big secret that the only reason Silverjet purchased Flyjet in the first place was so it could get around all the licensing issues the company was having at the time - i.e. lack of AOC.
To be honest, I'm not surprised that they intend to do-away with the 757's. As great an aircraft as they are, they don't particularly fit well into Silverjet's long-term plans with regards to cross-pond business class flights.....
Vidi, Vici, Veni. I saw, I conquered, I came.