Apple has never ever raised the price due to a new generation of CPU's. Intel CPU's also increase cores with newer generations. A-series chips also get more cores with newer generations. If they did that, the price would be 10's of thousands of dollars per device.One thing to note that the current 13.3" M1 MacBook Pro is $1699 with 16GB of RAM and 512GB of storage.
While it is nice to believe that for $100 more Apple would give us a 14" MiniLED display and an "M1X" with twice as many CPU and GPU cores plus another USB/TB port and MagSafe and HDMI, is that a realistic proposition? And if they did, who would ever buy the 13.3" M1 MBP?
Personally, I say "no" and "nobody" and that is why a presumed $1899 or $1999 price makes sense to me. And is one I am willing to pay.
tl;dr: If they didn't raise it when the bulk of the research and development was done (for the M1), they're not going to do it for M1 to M1X...at least because of the processor upgrade.
Apple also did not raise the price of the retina MacBook Pro after the first generation. It became a standard, and Apple kept the same price as the 2012 baseline MBP. They went to $1300 in 2013, which is $100 more than $1200 2012 baseline MBP. The following year, they dropped the price.
As cheap as solid state storage has become, it only makes sense that the baseline would have 512GB/16GB and cost $1400 or less...regardless of how much more powerful this year's CPU is. That is still overpriced btw, considering how solid state storage costs as much as mechanical storage from 2012. If they make it $1500, not enough people would buy a MacBook Pro.