Will there be a short message prompt when the other party cancels the family number? Can I only cancel the calling number?

There won't be, because the family number is one-way and there is no need for two-way binding. After A binds B first and takes effect, A can enjoy preferential treatment when calling B. In this case, B still does not enjoy calling A. At the same time, B can enjoy the same preferential treatment when binding A, but B also has the right to bind C as the family number and enjoy the preferential treatment when calling C.

Only the caller can cancel, because each number can be bound to a unique family number, but a number can be bound to different numbers at the same time. You choose your own family number, not who you are bound by.