Well, it would take R&D to see how many 7 string player are out there and if it would be worth a run of 7 strings and could they sell them all?
Also, with the left handed guitars, I can't seem to find the exact article I read but I think the percentage of left handed players is something less than 10%, but I think it was more like 5% or less. So with a niche market like the Parker Fly, it would never be advantageous to make left handed guitars. All that said they may do it just to be "nice" or some R&D guy says "yeah we could break even on it" and it might happen. My guess is that it will be discussed at Parker on and off but it will never really happen.
But who knows, maybe the success of the DragonFly bolt will create a market for a left handed DragonFly bolt. I could see a carbon free lefty being much more "do-able" without costing a left arm and leg.
My 2 cents. -Luc