This article is technically correct. Easiest way to verify is to try resising white-and-black checker patterns. All software I tried shows abrupt luminosity change when downsising checker pattern by factor of 2, and simple logic suggests that there should be no luminosity change. And if you try gamma correct with 0.45, then resize, then correct with 2.2, you will have expected luminosity like original pattern had.
But in reality it makes much less sense than in that specifically crafted pictures. Even "real life" illustration from the article is given in very contrast situation (a dragonfly photo on dark background)... and difference is still not apparent until both correctly and incorrectly resized pictures are shown side-by-side. My laptop screen makes more difference in these pictures from imperfect backlight and angles.
Things could change if one would use wider arithmetics (16 bits per channel), but software tends to use non-linear transfer function for high color depths, so this case is gamma correct. I didn't checked Photoshop for this, but I've tried to build gimp 2.10 from git, and it done things properly for high color depths.
The raw processing software, where it makes sense, heavily uses non-linear curves, too (starting with camera profile and white balance) and is generally color profile aware. For example darktable converts to Lab early and does most work in that color space, so said article isn't applicable to it at all.