Zach Lowe and Brian Windhorst (Hoops Collective) have recently gushed about the Celtics' historic run.
They will never get the same level of coverage as the Lakers, but that is because there are so many Laker fans out there, and it pays the bills.
The Ringer was founded by Bill Simmons, so I wouldn't worry about the Celtics not getting enough coverage. He talks about the Celtics more than any NBA team on his podcast.
The Mismatch is a spin off of the Ringer, and Kevin O'Conner, who used to write for CelticsBlog, follows the Celtics pretty well, without undermining their national coverage.
Michael Pena is a huge Celtics fan. He just joined the Ringer from Sports Illustrated. While he hasn't written a feature yet on the Celtics for his new boss, I suspect he has one in the works.