The Ace of Cups means also that a new relationship is about to begin. That you are about to meet a new person that you will get to know a little bit, depending on the area of life. If you ask about love, you will encounter a new person that you will maybe feel attracted to. If you ask about work, you will maybe get to know somebody that will introduce you to a new company or that you will meet somebody connected to a new company or work place.
Usually, and in most cases Ace of Cups doesn't speak about beginning a relationship with a person that we already know, but that this person is totally new. So when you ask about an old lover or friend, and the Ace fo Cups shows up, it means that you, someday in the future, will meet another person. No, You will not get back with him or her. And if you ask the same question for your lover, and the Ace of Cups shows up for his future love life, it means that he will meet someone totally new, and it is unfortunately not you.