Ford may not play Deckard the replicant. He could be the human that the Deckard replicant was based on.
That’s assuming there was a replicant, based on Ford’s character. I’m not convinced that was the case in this storyline. But, I don’t need to really go into it here, as we’ll see from how the storyline turns out in the coming sequel/
Perhaps it will be a “Prequel” and not a sequel. That seems to be a favorite of some movie makers. And a Prequel would help answer a lot of questions.