User blog comment:FairyRaven/Fairy Tail Chapter 337: The Golden Plains, Review and Commentary/@comment-2214433-20130628095736/@comment-77.195.192.48-20130628100747

I will explain you, the gate allows a person of one time to go to another one, but it also acts as an anchor and allow this person to stay either in the past or in the future.

If you cut this connection, a person who are not from this time will return in is own time. As Future Lucy isn't in the past anymore, the things done by future Rogue are cancelled.