There was a report released this week about rail service on the Portland-Bangor travel corridor. Two alignments are proposed: one is to use the lower road via Brunswick and Augusta, the second is an extension of the proposed service from Portland to Lewiston-Auburn. So the lower road is not "dead" yet, and I suspect the hi-rail activity was related to this initiative.
FYI, the alignment for Portland to Lewiston passenger rail has not yet been chosen; three are proposed: PanAm/CSX all the way to Lewiston, PanAm/CSX then ex-Grand Trunk via Yarmouth Jct., or ex-Grand Trunk all the way from Ocean Gateway in Portland to Lewiston. (As noted in the study, this 3rd option would evict Maine Narrow Gauge from their leased ROW on the Eastern Prominade.)