They were supposed to back in the 80s I think, when they electrified from Matawan to long branch. Somehow the money got squandered/it cost more than expected and what was supposed to be enough to electrify the rest of the line only made it to long branch. Also why the arrow sets can only run to Matawan (not sure if any are on the schedule anymore), there's a phase break (voltage/phase change) just south of Matawan where the catenary (overhead wire) changes to the newer style from the 80s and goes from amtraks 12.5kv 60hz to 25kv 60hz. The transformers on the arrow sets can't handle this changeover automatically like the alp locomotives so they're limited to Matawan runs. Also why there's triangle stickers on the arrow sets says what voltage they can run at, either "12k" for the Newark division (nec, njcl), or "25k" for the Hoboken division (m&e, Gladstone)