What's the point with that quite lackluster story in Endwalker?

[Lauront]

I remember that part of 5.2, but it also says in the wiki that many people mistakenly associate the Echo as being bestowed by her when, in "fact", all her shouting has done is awakened the fragment of the ancient within you which in turn unlocks the latent Echo, their power. I put fact in quotes because I honestly have no idea anymore.

True but when you take that into consideration, given that the MC is there when Urianger elaborated on its true nature, it makes the character's answer in that scene you linked even more baffling. Unless they just switched their braincells off whenever the echo was discussed?