Kind of, pricing seems to more closely follow Apple's consumer-facing logic, not the internal cost of development, bill of materials etc etc. So stuff like an upgrade from 256GB to 512GB costing $200 or 32GB RAM costing $400 over 16GB. I do think, though, the move to dedicated graphics only is why the 15/16" models since 2016 had such a significant base price jump.
The retina model settled back in at $1,999 starting price after 2012, when the Unibody was discontinued and an iGPU only retina model was introduced - though that did represent a permanent uplift of $200 as the Unibody had started at $1,799 as you mentioned. With the 2016 models, basically they only replaced the $2,499 (2015) model with dedicated graphics (giving it a $100 price cut but initially halving the storage to 256GB), while the $1,999 (2015) model was left on sale until 2018 but not replaced.
So now, with Apple Silicon, the opportunity is there to reintroduce that iGPU model/ $1,999 price point even if the model with the Apple GPU (Lifuka) continues like for like at $2,399. Whether or not they choose to do this I guess depends on whether the extra sales end up being worth it. A computer built around a SoC should be much simpler and cheaper to make than one with both an expensive Intel CPU and AMD GPU, even if it is a cutting edge SoC. I'm sure Apple won't sell themselves short, but if they target the 14" to take on the price of the current $1,799 (13") MacBook Pro, a scaled up 16" version at $1,999 seems quite a reasonable proposition.
