People will learn the true story if those involved decide to tell it. Then said people can absorb the new information and make of it what they will. I'm not sure how that changes anything for now?
And the film does try to subvert the audiences expectations, a few times. What do you mean by asking that question?
Well learning this information is quite groundbreaking. It kind of question the classic inspirational ending they chose, imo. They decides this "history" has no weight outside of Luke and Ben narrative, it does, I think.
The expectation of the mythic heroic persona/action/sacrifice at the core to these kind of movies, SW especially. TLJ kind of deconstructed it to just throw it back for cinematic value and, imo, undermine what the movie did up until the throne room. A lot of shaking for, in the end, a very conventional answer, imo.
Well, isn't the more important question: How dead is he? Is he even dead?
Isn't he a force ghost or even some kind of force god now. If we think about "force ghost Yodas" abilities in TLJ, showing up (iirc not in the see through ghost form but 'solid' looking) and interacting directly with 'reality' (blowing stuff up using force(?) lightning).
With this in mind you could even argue that in his current state he is not longer bound to the 'limits' of a body and could be even more effective in the war than before.
He might even be able to play his 'force projection stunt' against Kylo or the First Order again.
I was responding to people saying it made him look like a God because people of the galaxy (FO, rebels etc.) thought he was still alive. That this illusion, a completely idealized and constructed narrative, made his tale work.