The existing Replicant models can only live for a maximum of four years and don't age, that is the reason why they were rebelling in the first place. As I said before in the other thread, if Deckard appears in this and has aged, then he can't be a Replicant. Quod erat demonstrandum.
Which pretty much ruins the "is he/isn't he" in BladeRunner and trashes one of the features that made it so noteable in the first place.
I have no preference regarding the replicant debate, although the signs were there that Blade Runner's Deckard was indeed a replicant, and the way it is revealed (unicorn dream/origami) is certainly very poetic and one of my favourite features in any movie ever made.
Ridley Scott, who is involved in the sequel in an exec producer capacity, also strikes me as a pretty stubborn guy, who knows what he wants and will not deviate from it. I don't see Villeneuve, who admitted he revered the first film and Scott's vision, or anyone else for that matter, convincing Good Old Ridley that his take on 'RepDeck' was a mistake and needed to be replaced with a new canon.
Something tells me that the Deckard Ford will be playing in Blade Runner 2049 will not be the Replicant we saw in Blade Runner. He might instead be 'The' Deckard, a human template used to build RepDeck. Or he might be an even more advanced model of replicant, who can now age and shares a regular human's life expectancy.
I would also like to point out that the shot of Ryan Gosling's hand toying with the piano in the exact same way Deckard had in Blade Runner is certainly anything but an innocent coincidence, especially in a teaser that only contains a handful of shots. Also note the similar taste in fashion and haircuts. All this might hint at shared traits (memories, tastes, personalities?) between the two characters. Maybe both characters are extensions of a single identity or entity who will be at the centre of the film's plot.
Just speculating, of course...