MusicBrainz Picard 2.2 has raised the macOS minimum system requirements to macOS 10.12. While you've noted the new system requirements on the homepage, you've forgot to actually update the real binary system requirements embedded into the app.
the 'LSMinimumSystemVersion' entry in your Info.plist file should be set to 10.12
as it is currently, you can still launch the app on any older operating system, resulting in crashes and/or undefined behaviour, and the user might not even know what the problem is. properly setting the LSMinimumSystemVersion will make the app refuse to launch on any macOS version that is not new enough,