I can not imagine Walthers ever tackling one of the (semi) famous named trains of the East. In nearly every case, what limited fame these trains garnered came during the steam-era with their consists generally being pulled by massive steam locomotives each unique to their particular road. Walthers likes to use F's or FP's on its named trains because the engine shells can be re-used over and over by mainly just changing the shell's paint scheme for various trains. The famed eastern steamers were all virtually unique to themselves and if attempted would have to be individually tooled from the ground up and sold at brass prices to justify such tooling.
At the same time, save for those of the NYC and PRR, most of the eastern named trains like the CNJ's Blue Comet and Queen of the Valley, RDG Crusader and King Coal, NH Comet and Shoreliner, LV Black Diamond and John Wilkes, B&M's Flying Yankee, plus many others of their ilk, plied only short runs and drew little national attention of the sort that the semi-transcontinental trains garnered. As such, their market today would be vanishingly small and the corresponding selling price would likely be several thousand dollars per full set (locomotive and cars) if accurately rendered.
Perhaps the final nail in the coffin for such an idea as Walthers considering an eastern named train as a future venture is the fact that most of the really famous eastern named trains' locomotives, and in more than a few cases the entire trains consists, have already been rendered in brass. I can not imagine a plastic versions drawing much of any sales if one could obtain the brass sets for the same, or even a somewhat lesser, price.