Earlier quoted context omitted.
How could it? Do you expect them to run some sort of headless Photoshop VM?
well, it's able to display 3d files and images, so why not add some viewers for diffs ? https://github.com/makezonefablab/MakersBook01_MusicBox/comm...
In general one should not use PSD in an open source project, because it requires costly proprietary software. Also does not run on Linux