Earlier quoted context omitted.
Whatever wizard at Apple came up with "the number of monitors" as a distinguishing difference between price levels should get a pretty big raise. It's perfect segmentation, most people don't care, and those that do will pay.
The Touchbar in the 13" MBP counts as a display. So the Pro already runs 2 displays and can add a third. The same GPU+CPU is in the MBA which only runs 1 + 1 external display. It't not a limitation of GPU or whatever they want you to believe. This is pure market segmentation.
(Hell, is the central GPU even running the touchbar, or is there a specialized display circuit just for it?)
That said, my reaction to this whole thread is pretty much "I guess multiple external monitors is a reason to upsell you to a Pro machine" so we agree on that point :)