You still have to have the pieces in effect for the leap to take effect. Atlanta's happened to coincide with a coaching change. Even then, those two teams spent years and missing in the lottery before they finally had the foundation in place for it to be one missing piece away from it coming altogether. Their fortunes and leaps didn't just happen overnight or in a 2-3 time frame.
As much as Memphis overachieved this year, I still don't think that they can take the next step unless they can JJJ to become the superstar that they think he can be. Same with Sacramento and how they needed Bagley to elevate them. Good guard play alone isn't enough to take you somewhere these days unless they're paid with a elite level big man or wing.