Yes and no, a detailed article covering the terms of the debate is here:
http://healthaffairs.org/blog/2016/09/19/the-politics-of-med...
Most relevant quote:
"One bargaining chip to attract market-oriented Republican votes was the so-called “noninterference clause”—a provision drug manufacturers had a major role in writing and getting through Congress—which banned negotiations between Medicare and pharmaceutical companies on drug prices and prevented the government from developing its own formulary or pricing structure. Instead of CMS negotiating on Part D plans’ behalf, prescription drug plans compete for enrollees and negotiate directly with manufacturers."
Part D (and presumably Part C plans that offer prescription coverage) negotiate with the drug companies individually. CMS cannot negotiate en-bloc for all the Part D plans. Therefore Part D plans have the same leverage as traditional insurers, which is to say some, but not nearly as much as All-Of-Medicare has.
The VA and Medicaid do regulate/negotiate drug prices, but those are much smaller populations. I think something like the VA system might work, but you'd have to have politicians willing to take some political risk or find a way of isolating drug price negotiations from political pressure. I think in this political climate, that's a really tall order. Remember when "If you want to talk to your doc about end of life plans we'll reimburse you for the visit" turned into Death Panels? I suspect we'd see something similar...
EDIT: and yes, private companies with a formulary are a great way to isolate yourself from the political heat, but you then lose the negotiating power government has ;)