[cmurf]

The FAA doesn't care about the name. They can require a type certificate specifically for the 737 MAX series, separate from the 737 NG series.

And a type certification isn't the only way to require additional training. For sure there are meaningful differences between the 757 and 767, despite sharing the same type certification, and pilots do go through that difference training. There are numerous examples of this.

Where Boeing probably wants to be, is in the vicinity of the regulatory distinction between the A320 and A320neo. It seems really unlikely to me that any 737 NG to 737 MAX transition training burden, is going to approach that of 737 NG to A320neo transition training.