I think you're overestimating the kinematics of missiles. When they're fired at targets that are flying much faster and higher than the platform they're launched from, their speed and range won't come anywhere near their top advertised parameters. They would need to get close to have a chance, and a VLO platform unlike the B-1 or Tu-160 would have a good chance of avoiding that.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.
You're not trying to outmaneuver any missiles here. You're trying to launch your payload and then outrun them.