This rumor has circulated around the internet several times in recent years, but so far there has yet to be any real evidence presented to seriously support the idea.
One thing it clear, however, and that is Walthers, nor its annual consumer catalog, are any longer the real go-to source when wishing to obtain model railroading items. Once upon a time Walthers could be counted on to provide hobbyists with virtually any and everything one saw in their catalog...and do so within a week. Today what stock they do maintain is certainly not in any depth and a very high percentage of items are listed on back-order with an arrival date noted as "unknown". Now I understand that many businesses these days follow the current business model that says maintain minimal stock However, this highly constrains a hobbyist's progress when he can not obtain from the presumed premier supplier some critical items he wants for his layout. At the same time Walthers' items are mostly overpriced relative to street prices found on the internet and elsewhere.
I would add that in recent years Walthers seems to be turning increasingly toward offering high-end locos, cars and whole trains, the latter approaching what were brass prices not all that long ago (they are not alone in this either). Paying upwards of $1,000 for a set of plastic diesels and some accompanying cars says to me that Walthers' current business direction is heading more and more toward an elite collectors market and no longer is targeting the average hobbyist. Just how long they can stay afloat in a dwindling hobby market remains to be seen, especially considering the demise of virtually all of their regional distributors and allied hobby shops. Nevertheless, I don't anticipate that Walthers will close its doors anytime real soon.