I think if he is good and cute enough, he will not have trouble finding a good girlfriend who matches him (age, family...). So neither LZ nor we need to worry too much about his future...
However, what LZ should worry about is, her own way dealing with her love and her life. Is it the urgent moment for her to make a decision? Should she take this decision alone or with her boyfriend? Is the man in China absolutely better than her BF? LZ could always meet better and better men in the future, will she hesitate every time?
If one love is not the right one, I believe that will finish one day or another. It is true that if LZ insistes with her BF, when she really breaks up with her BF, she will become older than now. But if LZ can not persist in a relationship, make an effort, take the responsibility, LZ will fail or unsatisfy in any future relationship, therefore she could not find the peace and the meaning of a relationship.