Answer:It says Romeo's love has died; it foreshadows that he loves Juliet.
What the prologue fully says is “with tender Juliet matched, is now not fair." Which means that since Romeo can compare Rosaline to Juliet since he’s now met Juliet in the story it is clear that Rosaline and Romeo's feelings can compare to Juliet and his feelings.
I hope this helps :)
