The Boston Symphony’s board didn’t fire Andris Nelsons as its music director. Not exactly. They declined to renew his contract because he and the BSO weren’t “aligned on future vision” — the board’s own words, offered without apology. Not artistic differences. Not budget. Not performance. Future vision. That phrase is doing a lot of work here, and it’s worth thinking about, because it signals a structural institutional shift, one that appears, in different vocabulary, in many of the stories in arts and culture this week.

