I would bet money we will never get an "official" answer as to whether or not he's redshirting until after the entire season. Why? Because when I was working for The Chronicle I wrote a couple articles on the then-redshirting Alex Murphy and Marshall Plumlee and directly asked Coach K about them, and invariably got a response along the lines of: "Redshirts do not have to be declared until after the season. If either player earns playing time they'll get it." Now, the players themselves definitely knew they were redshirting and told me so (
https://www.dukechronicle.com/articl...-redshirt-year), but the staff never made anything "official" until after the year. (Note that more recent history with Amile Jefferson's medical redshirt also bears this out.)
As far as speculation about Baker, when I watched him play in Mississauga I was pleasantly surprised with his game, albeit in an exhibition setting... although there were clear moments where I watched and said, "That's a mistake made by a guy who just isn't ready to play at this level". So my gut feeling was that he would redshirt. However, given the issues we've seen in the exhibitions and heard about from practice with 3 point shooting, I wouldn't rule out his playing if either Jack White or Alex O'Connell can't definitively claim the role of "instant offense 3-point specialist" off the bench after the early season. So I'd say it's unlikely, but not impossible, that he sees the floor this year.