No. Porzingis will be a good player and gets a lot of attention because he's in New York, but Fultz is a different class of prospect. We are talking about somebody on the Anthony Davis/Karl Towns/Ben Simmons level here.
We're also talking about a Point Guard, the most stacked position in the league. This draft alone has more than 5 interesting PG prospects, and that trend won't change for the forseeable future. The draft is a crapshoot, after all.
I wouldn't do it, mainly because I'm not that high on KP, and believe Fultz is the better talent, but I wouldn't rule it out, either.