Of course, because when it goes F2P, the price and risk barrier to entry is even going to be lower than WoW's. I'm suffering through some of the same annoying bugs as the rest of you but I'm still hesitant to drop the coin on MoP because that's an extra $30 initial entry fee to start it (since I'm not getting this month's swtor $15 back even if I unsubbed today).
The idea of F2P is to not have free players but to have players that will pay for content. The barrier for that content is still money. When they release new content, for F2P people, it will be no different then what you just said. You will have to drop coin on that just like MoP.
Even still, 50 million people is more then ambitious guestimate