When did it happen before?
I agree that the Pelicans don't know what they are doing, but they shouldnt just automatically trade a franchise player for the first pick in the draft. I could possibly see 2017 brooklyn pick, 2018 brooklyn pick, smart, brown, + memphis pick, Zizic. for Davis. But not just the number 1 pick. Davis is also locked under contract for many years, so the Pelicans have options.
Also Westbrook is that franchise, if you lose him you undermine the franchise and quickly become the most hated person in OKC. And again you don't trade a 28 year old, likely MVP, who just averaged a triple double for a player that maybe one day can become an all-star. That is insane.