Seems like the Mac build is still broken. Adding an .app at the end of the mac folder makes it launchable, but it says that it’s damaged after a short while. Here is the error message which I get in the Mac Console maybe it helps. Seems like a file is missing.
Non-fatal error enumerating at <private>, continuing: Error Domain=NSCocoaErrorDomain Code=260 "The file “Extensions” couldn’t be opened because there is no such file." UserInfo={NSURL=Extensions/ -- file:///Users/bvoigtlaender/Downloads/itchZips/mac.app/Contents/, NSFilePath=/Users/bvoigtlaender/Downloads/itchZips/mac.app/Contents/Extensions, NSUnderlyingError=0x7fcb0ce36680 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}