I believe the way the new MacBook Pros work is that the screen will get about as bright as the previous generation when at 16 clicks from bottom (i.e. 100% brightness as set by the user).
The extra 67% is provided automatically in situations that need it. For example, if you are in direct sunlight, the screen will get brighter than you can set it.
I haven't got proof of this, but this is what happens on the iPhone 7 and Apple Watch Series 2 as confirmed by DisplayMate. When they release their report for the new Pros I am sure they will mention it.
The point of this feature is to save power, based on the premise that you would never need more than the 'normal' (i.e. equivalent to the previous generation) full brightness for indoor use.