I don't buy that its because of trump.. I also don't buy that its just a ploy.
My feeling is that the most simple explanation is probably true. I expect that he and his goverment are in increasingly deep **** with their economy and resources, and since China started to take a harder stance on them, they have just been going downhill fast. The simplist explanation is that they know they can't hold out that much longer like this, so they are going for a peaceful situation that keeps them in power, but frees up trade and economic ties a bit, so that they can survive as a nation.
China will never let them fall - they are to important to China, so unification is not an option. They will make some steps in the right dirrection, sanctions will be lifted, and then they will keep going as before, just treading a finer line.