I picked up an axle from a 2015 GX460 and installed it today without issue. It seems they do work, despite completely different part numbers and no physical confirmation I could find that they are interchangeable. The inner CV is much larger and a complete redesign from the original. The outer looks identical. Length appears to be the same. I was worried as there are some visible differences with the inner stub axle, but spline count and overall dimensions seem the same. I am quite pleased with the updated inner CV, I expect it to hold up better than the original.
Hopefully I don't run into any issues long term and perform this "mod" at your own risk. I wanted to go this route as I have access to low mileage factory parts from a local scrap yard. I prefer used OEM to all of the China parts that are available, especially when it comes to CV's.