He was and wasn't. He was asked if he could do road games along with home as NESN was going to one person doing both and he said no. So in effect he took himself out of consideration.
10 years ago Bruins TV producer Doug Wheeler retired and was replaced with Brian Zechello who wanted one team for both home and away, under orders from Tom Werner. My understanding is Dale was asked if he could work all games home and away and he said no, so no official offer was ever made. He was the first choice for NESN. Jack also wanted to work more as he had young children.
The only reason there were separate announcers for home and away goes back to when games were split between NESN and TV38 and both stations wanted their own announcer. Fred Cusick shocked everyone by deciding he wanted to do ROAD games as he did not look his new position at Fleet Center on Level 9 and Dale was given the home games. When Fred finally retired he was replaced on TV38 by Dave Shea.
Because of the lockout Dave Shea took a radio job with the new Washington Nationals ( and he was fired after one year ) but NESN had already hired Jack Edwards to do the road games.
That was an era of major change at NESN as the new Red Sox owners put their own people in place after taking over in 2002.