May never come back? Celtics is the only one of the big sports they carry whereas NESN has the two biggies Red Sox and Bruins. I understand with the big changes there will more interest in the Celtics however when CSN went away there was nary a notice of it here and the Celtics had a great season. If DISH receives enough calls or emails etc about it's not impossible they would take another look but remember we are only talking about people who subscribe to DISH and are in the CSN area to get it or perhaps those that get the NBA PASS.
This would not apply to true fans but the NBA has a problem about regular season games - many are satisfied with a few games on TNT or ABC etc till the playoffs - when then they aren't on the RSN anyway.