The formats listed on the ratings pages mean nothing. Do you really think 1430 WKOX was a News” station too before they went to a Spanish language format, and the “News” moved to 1200 WXKS?
Then show me where WBUR and WGBH are classified as "talk" stations. Pick a documented source.
They're called news stations because they report the news. They don't have a host who talks non-stop. They have a staff of award winning journalists who report the news. NPR doesn't have a "talk" department. They have a news department.