How do you know what the EVF will be like? And isn't the AF tracking on the 1Dx3 (which this is supposed to share) considered very good?
Do we actually know it's cheaper to build them? But anyhow, it's not the only reason. They saw the way the market was going and noted it opened up new opportunities (some technical, some business). Of course launching a whole new line means they can charge more, but then they have to recoup higher development costs too. I don't think it's as simple and cynical as you're making out.