It is hard to know if the Suns will miss Bates-Diop, because when you look back at the season so far, it is hard to remember a time when he was out on the court when good things were happening. He's without known for his defensive ability, and yet it was Nurkic and Grayson Allen alongside the "Big 3" who produced the best team numbers on that end of the court.
Bates-Diop did start eight of 37 games played - the second most he's managed across four teams played for so far in his career - and in that time he did exactly what he was signed to do. Get out of the way offensively and pick up some tough assignments on the other end of the court. So he may actually have a case to be the player the Suns will miss most.
Interestingly the Suns also had a better defensive rating (113.6) when he was on the court as well, compared to the 116.0 (16th in the NBA) they have managed as a whole this season. If this roster remains fully healthy from here on out, then Bates-Diop isn't going to be missed. That is just the reality of the situation.
But if a couple of bodies go down for any length of time, the absence of Bates-Diop may actually be felt. He was a competent backup behind Eric Gordon, and the organization need to ensure they have an option on the buyout market in mind, such as Danuel House Jr., to ensure that they don't regret letting Bates-Diop go at the deadline.