The D&D branding itself will bring in the wider audience, regardless of the system they use. It has been polled anyway. Only 8.5% or 9.5% wouldn't play the game due to the system. Turn Based wins in polls - both in "prefer but will play regardless" AND in "won't play unless turn based"
Risky. I'll put up with TB if it's a series I'm already invested in or otherwise have a reason to be specifically interested, but if it's something that might've caught my attention and was 50/50 as to whether or not to buy it would push the consensus towards not interested. Maybe if I was coming from a D&D background I might have a different opinion.