A supersonic bomber like the B-1 or TU-160, even though its fast, still isn't going to outmaneuver any missile at all, so I don't believe the PLAAF will decide to degrade stealth by adding a beak or folding stabilizers simply to design an airframe which is capable of between mach 1 and mach 2. It is much better to simply maximize stealth, a flying wing shape with one continuous leading edge, similar to B-21 or B-2.
There is no point in sacrificing stealth just to make it a little faster, missile will catch up to it regardless.