I've done that trail at least 20 times now, on my road bike with 23c tires. It gets messy but I don't mind. I'm of the opinion they should leave it as is, or at most fill in the holes. Paving it would ruin the sense of isolation you have while riding it. Gravel tends to cut tires. I will say though that after starting in Brewster and riding the entire length of the N/S County Trail, it isn't what I want to be doing to go that last mile, although there are about 25 more miles for me to go to get home in Brooklyn.