It's the first thing we were told about him "after the stories of the Fetts ...
another warrior emerges"
That's the whole set up....
Then later reaffirmed by Favreau that it's a new character.
Reaffirmed by Pascal who reveals behind the scenes and narrates how when he saw the first Illustration he automatically thought he was playing Boba Fett, only to be told, no it's a new character.
Why would he narrate a behind scenes story that potentially gives away the "reveal".
He wouldn't.
Also and probably most important thing; he looks and sounds
nothing like him!
I feel a bit sorry for those desperately clinging to that delusion (and their I told you so moment that will never come) they are really setting themselves up to be disappointed I guess, if that's what they are hanging on to or hoping about this show, sad.
That said, I wouldn't mind if wandering through the Dune Sea, he runs into a horribly scarred bandaged up old warrior with a Māori accent, who has secretly been mentoring him.