I am quite certain it does not need gettext. It has NO_BUILD, so it most certainly does not need gettext-tools (used during build to handle build-time things like converting .mo to .po).
It may need a USES=gettext-runtime:run if something uses bin/gettext directly, but I doubt it. It does have .mo files, so it most likely need a USE_PHP=gettext or USE_PHP=intl.
This is not needed, it is added automatically by the SUB_FILES below.
There has not been a "PATCHLEVEL" variable defined for about 5 years, it maybe be time to remove those two lines.