Will the destruction of future Universe 7 affect other timelines in 20 years? In the Black Goku arc, the future Universe 7 was destroyed by Zeno. Since Beerus said something along the lines of if a god changes an event in a timeline then it changes in all the others, does that mean that in 20 years the current Universe 7 will be destroyed?
In Dragon Ball, when a person travels in time it creates alternative timelines/ realities. So what Beerus destroyed was an alternative timeline/reality, which has no effect in the current timeline of universe 7 therefore the current timeline wont be destroyed in the future.

http://dragonball.wikia.com/wiki/Alternate_timeline