All your UA points will renew for another 18 months if you have any activity on your account. Since you said they expire only mid next year (about 18 months from now), you don't need to rush in generating these new points as you would win more time to plan your Japan/Taiwan trip if you, for instance, sign up for MyPoints later this year. Obviously, there is no guarantee UA won't change their award chart and the leg you now need 15k points might require more points in the future.