I think it's intentional, they seems to want us to go deeper than the surface to get some infos.
Tenzen reaching floor 100 is learned by you only after you get all the jewels
Rasho reaching floor 50 is learned by you only if you talk to him afterwards.
You learn of the Hellfire phoenix's family only by doing a sidequest in Ala Ghiri, which I don't think is even a main sidequest and there isn't even a synopsys on it so you either read it or you lose it.

Remember how we understood that the Crooked coin was important? It's a sidequest that has no synopys either and it is quite important because the main sidequest of the dotharl talks about how their echo works in their belief and you would think that they simply pull out reasons out of their backs when the prophecy isn't fulfilled, yet that sidequest shows you that is not all true and some are crushed by this belief.

Anyway yes I think there's some intentional misdirection at work here, but that it just as a supposition