She will miss you but she won't get back to you because she has found another person. Unless the relationship with the other man doesn't go well, she might not return or she might decide not to return even if it doesn't go well.
Missing someone isn't a sure guarantee that person will return.
The reason for her behavior of kissing the man the first time they met might result from the cause of the breakup.
Continue with NC until you find out it is time to move on and let her be.