Considering we have 1000 years to work with, I don't see any reason why we would need to start a seventh timeline. Previous timelines have lasted for years, and the main reason why the fifth was stopped was because of the legends retcon.
What happened in the fifth timeline was they did a "time skip", where they jumped ahead several years. Not sure if they are going to do so again, but like I said, I don't see the site starting a new timeline anytime soon, considering the sixth just started a few months ago.