Why does Bran Stark feel that Jon Snow “needs to know” about his lineage?

Question

In Game of Thrones S08E01, we're all enjoying the drama around Jon Snow's

learning of his true parentage/identity.

Obviously the news creates turbulence for Jon's love life and for his humble position as Warden of the North or whatever. And Jon seems literal-minded enough that I would expect him to treat this news as a Big Deal, he doesn't have much moral flexibility unlike Cersei or even Jaime or Sansa. So it makes sense to me that he freaks out as soon as he learns the news.

Why does Bran insist that Jon needs to know this news? Bran is insightful enough even without his Greensight to know that this news will only cause (really poorly-timed) drama. It's not like Jon secretly wishes he could have a higher station in life; this news can only complicate and darken his life, plus it will prolong Westeros' political instability. And Bran doesn't seem like the type to care much about

potential aunt/nephew incest, nor about whether his brother gets to be king or not.

So why does Bran seem to feel urgency to make sure that Jon a) knows about, b) believes, and c) presumably does something about, this news?

Answer 1

Bran is now the last greenseer, as the Three Eyed Raven was before him. This gives him the ability to perceive events in the past, present and future.

Although we as viewers will not know for sure until more episodes of the final season have screened, we can assume that in universe Bran has seen how his actions will influence later events and therefore he has seen that it's important for Jon Snow to learn about his heritage now so that later events (that will give Westeros a chance against the Night King) will come to pass.

For example, perhaps Jon's knowledge of his past will cause him to make different leadership decisions, adopt different battle strategies or will alter his relationship with Daenerys in a way that increases the chances of a better outcome in the long run.

Answer 2

Because they might not have time to do so later on

They are about to go into a huge battle against the most fierce opponent Westeros has seen in thousands of years. There’s a high chance that Jon and/or Dany could die against the White Walkers and their wights. To get the news out as soon as they can is the best bet so more people know the truth if it will matter at the end of things.

It’s also quite important for the North, they don’t trust Dany and if it turns out that Dany would bend the knee to Jon that whole problem goes away. Of course it creates a further problem with whether the Northerners will trust Jon or not but that’s probably less of an issue than the Dany one.