As a fan of the NBA, I love it.
As a fan of the Celtics, ugh. That's going to be a tough out. Would have been less concerned if Lillard ended up in Miami.
As a conspiracy theorist, this is better for Miami in the long run. In 2 years Lillard will have fallen off the cliff (or be too injured to get them a title), causing Giannis to hit free agency and go to Miami.