This feels like Monte Carlo rendering applied to rasterization. I'm wondering if it's a brand-new or a well established methodology
Monte Carlo in 3dgs is established enough that Spark [1] has been doing it for a while in the browser.
that goes all the way back to the Kajiya rendering equation https://en.wikipedia.org/wiki/Rendering_equation
It's not new - that was sort of my point with my other comment.
At least if it's progressive (so refines and resolves over time), this has been done with pointclouds in the VFX industry in GPU shaders for years in terms of stochastically drawing different points so eventually the whole point set gets rasterised to a fidelity threshold.