Stella Vegapunk says to Robin that dream of Ohara was saved so according to Vegapunk there’s enough books saved that basically the entire mission of Ohara is fine.
the books obviously have the method of reading poneglyphs in them and they also have the history of Joyboy that Vegapunk talking about
That’s it. This is Oda’s intention. Oda wants us to think everything Vegapunk said was correct. And so you having an issue with this is your problem