I can't speak for providers other than mine, but Unitil in at least the seacoast has crews (usually Asplundh) cutting trees back constantly - I see them or the results of their work all the time. They called 3 weeks ago asking to trim my trees away from the power lines, and it's a small apple tree.

The town and/or homeowners/landowners have to allow the utilities to do tree trimming work. Can't fault them if they are asked and told no. The large storm in December was the first time we've lost power here for any length of time since the last huge ice storm in 2012 I believe it was.