RE: 6spd implications for Charger?
Even if the transmission could fit into the Charger I somehow doubt that Chrysler would offer it as a factory option. They never really have marketed the Charger as a 'muscle' car and pure performance oriented. It was marketed as a bad arse sedan and it is. They're marketing the Challenger as a muscle car with clear homage to the Challenger of the '70s and thus the 6-speed. They want anyone who wants pure performance to grab a Challenger, and those who want performance with family sedan convenience to get a Charger.
Entirely personal views with no proof to back any of it up I just don't think they'd offer a factory option 6-speed on a Charger. I doubt many would pick the 6-speed Charger over a 6-speed Challenger anyway. If the Challenger wasn't being built it'd be a different story.