From my end using Windows 10 x64, I am seeing this - https://i.imgur.com/9nbqQVF.png There's also missing edge detection filters, but the edge detection that was already there makes the other ones obsolete, so that can be disregarded. Brightness/Contrast filter doesn't adjust color saturation in the way that color adjustment do, and that helps some artists work with it. What happened to the brightness/contrast curve filter?
Brightness contrast has since 3.0 been implemented in the color adjustment curves, but we never wrote a proper converter. The converter has been written for both and thus these obsolete filters could be removed.
I looked at Lightness on one of my file which didn't convert right, but I can see the curves remained the same, but with different results. Actually, on the file I have made with a bazillion of filter mask/layers, it looks like I might have to slowly fix those.