NBC Sports Boston has been hit hard by a decision from parent company NBC Sports to slash its digital and regional cable staffs the past two days. Nearly 20 on-air and behind-the-scenes staffers at NBC Sports Boston were laid off Monday and Tuesday, including longtime anchor Gary Tanguay, Celtics sideline reporter Abby Chin, host Danielle Trotta, and Celtics reporter A. Sherrod Blakely.