It probably is 600+ but he said that they needed to net that many. The limiting factor to the airline's growth is the training department. In 2017 we will be caught in a transition of sims from one building to another. Once the new sim building is up and fully running we will have the ability to pump out many more than that number.

MAX training will be a home study course of about two hours

Apparently it's a very easy transition from the NG with the big differences being a longer time for engine start (think B717 for the FAT pilots), and it's also VERY clean and slick. I know one guy who's working on the MAX program and he's really pushing for simultaneous flap & speedbrake usage (which the aircraft is reinforced for as is the -800 and some -700s).

They avionics make it even easier to fly than the NG from he says.