First of all, I have no issue with the bolded part of your statement....that isn't really speculation, or a hypothesis since we have decades of data to validate the notion that the climate is in fact warming.
As far as your assertions regarding the warmer SSTs east of Japan inducing a faster northern jet that is making BM tracks exceedingly difficult, that may very well be true, but I don't that accounts for all of the missed opportunity....there are always going to nuances within the larger scale flow due to variability; CC doesn't prevent that. Frankly, having a confluence or a PV lobe too close in ME is just bad luck. Maybe your point regarding the jet is part of the reason why these storms aren't phasing proficiently, but we haven't had great ridges out west, either.
Here is an excerpt from the blog post that I made on Friday night, cancelling this storm (never bought in for this reason) as guidance was ostensibly converging on a major NE blizzard.
https://easternmassweather.blogspot.com/2025/02/major-storm-threat-next-week-likely-to.html
However, there is ample reason to doubt that this system will phase proficiently enough with the southern stream wave moving up the coast to impact the forecast area in a major way. Note the similarity in the forecast position of the PNA ridge next week in the above image to that which preceded the major storm threat of January 11th.
This has been a very prevalent feature in the seasonal mean, which may at least partially explain the relative absence of major snowfalls across the region despite the relative cold temperatures.
In closing, I have a question for you....why do you think the 1950s and 1980s, especially the 1988-1992 period, were so poor for snowfall on the east coast?