Let's not start celebrating too early. Rumors have it that he's giving New Orleans a hard look:
Steve Bulpett: Celtics will definitely have interest in Greg Monroe, but key will be what’s most important to him. Of logical suitors, Celts can offer most ($8.4 million DPE) and good chance at making Finals, but hearing he could be looking at greater opportunity for minutes in New Orleans.
Makes sense. If he does well then he can get another big contract when free agency starts this summer.
Well now that NO traded for Mirotic though, Monroe's potential playing time there just took a big hit, as well as the chances that they would resign him.
The first part is somewhat true, but they like playing AD at PF more (more accurately AD prefers it strongly) and Mirotic is more of a PF than a C, and even with Mirotic they still only have two true bigs who are healthy. So minutes are still largely there.
As far as resigning him — they can only do that (for much more than the minimum or so) if Boogie walks, and that was true both pre- and post-trade. As it stands, they were and still are projected to be a tax team if Boogie signs at or near the max, and would only have the big MLE if he left, whether they had Mirotic or Asik.