Single Status Update
With all due respect, I wouldn't bother them with such a frivolous request; they are quite busy where they work and do not need me meddling into their affairs. The designation of the line has only existed since the late 1950's so there is nothing historical about it. Now if we were talking about the elimination of the actual elevated line, then you would have a point. Also if the designation had had some sort of historical significance, then there could be an argument; however, Duke Ellington did not write "Take the Train".
Personally, IF this plan were to be implemented, I would be in favor of the designation simply because it would be easier to notify the thousands of people who use the line between Marcy Ave and Metropolitan Ave of the relettering and the new route scheme than it would be to do the same on Queens Blvd with 1+ million riders per day.