The MACOSX_BUNDLE_INFO_PLIST override doesn't seem to work anymore in CMake 3.14. I noticed that after upgrading my local CMake from 3.9.1 to 3.14, the Mac app I wrote using Qt suddenly had awful font rendering. This is solved by adding NSPrincipalClass NSApplication to the info.plist file. (see also https://stackoverflow.com/questions/34465506/retina-support-in-qt5-on-os-x).
However, info.plist is generated from MacOSXBundleInfo.plist.in, which I had already added to my own source archive and pointed MACOSX_BUNDLE_INFO_PLIST to it. This no longer works. I verified this by renaming the MacOSXBundleInfo.plist.in in /Applications/CMake.app/Contents/share/cmake-3.14/Modules/, after which I got the error that it could no longer be found.
I was able to work around the issue by editing the template directly in the CMake install location (since I'm admin on my own machine), but this is obviously not ideal.
I'm not sure in which version between 3.9.1 and 3.14 this functionality broke.