Lensrentals measurements of MTFs on the 5DSR, with the AA-filter neutralised, and 5DS, with the AAfilter on, under the same conditions
As stated in the article that was not a test for extinction resolution, but for resolution at MTF50. I've already pointed this out. Did you not read the article? Do you not understand the difference between MTF50 and extinction resolution?
BTW, you can sharpen any image and increase the measured MTF50 point.
and AP's measurements on the Sony RX1R II with the AA-filter off, standard and high under the same conditions are controlled measurements
That's a very different LPF design. I think it's an interesting result, but also trumped by the fact that two 24mp sensors with/without a traditional LPF show the same extinction resolution.
We can go round and round forever. If the 5DsR (or D800E) truly showed higher
resolution (traditionally MTF10), as opposed to merely higher sharpness (MTF50), it would be easy to spot in some of the many test images at DPReview and Imaging Resource. But it's just not there. The images are very difficult to discern even at 100% and 200%, and impossible after a light sharpening pass on the AA filtered versions.
An AA filter means resistance to aliasing, moire, and higher sharpening settings when you do sharpen. No AA filter means some aliasing, occasional moire, and lower sharpening settings. In the case of high resolution sensors like the D800/D800E and 5Ds/5DsR you're never going to see aliasing or sharpness differences in print even if you don't correct them. The only thing that will stand out in print if you don't clean it up is moire.