Yes, we are.
The whole “not having a premier center” aspect was overstated. As I've mentioned before you don't need an all-time big man just to win a championship if all the other pieces are clicking, you just need a serviceable big who can do the “nooks and crannies” on offense and defense, which Hayes has proven he can do that.
Outside of the Bucks, Nuggets, and Celtics, seven of the last ten NBA champions did not have elite big men. Boston might not even count in that regard as having an elite big because KP was pretty much injured for most of that Postseason run.
The only real threat in the West is OKC. Denver is a sleeper, but this isn't the same Nugget team as the previous two seasons that invoked fear, while Houston and Memphis aren't trustworthy come playoff time because of their youth and inexperience.
Warriors, Clippers, Kings, and T-Wolves aren't even in the picture in terms of being someone to watch out for in the Postseason. Dallas might not even make it, depending on Kyrie, who now might be out for the rest of the season.