I am afraid it is just the first step.
Mills is signing him not for the rebuilding, but competing. It means he really wants to do something now and is willing to spend some resources to accomplish it. Salary cap is the most moveable resource, and when it dries up (it means we are in cap hell) but we are still sub-par, then we have to do more.
Next sensible choice is to move players for another one. But since we overpay our players to get them here in the first place, we cannot trade them away. For example, THj is 18mil player, but with 15% trade bonus it will be 20.7mil, right? I am not sure we can trade him away like a 21 mil player. It will be too hard. It requires him to be a superstar.
That means we are struck with the players and we have no way to go out. You don't have cap and you cannot trade away your players to go rebuild. You only choice is double down and win now.
I think we all know too well what the third step is.
Trading away our first round picks to get more help, hopefully we can go over the top.
Knicks didn't trade away the picks immediately. We did it because we didn't have any major asset we wanted to trade away at the time.
If we start to trade away picks, I think we can safely assume we finally undone every "damage" Phil has done.