The init script(s) provided in FILESDIR for sys-apps/xmbmon has a license of GPL-2 but GPL-2 isn't within the LICENSE variable of the ebuild(s):
files/mbmon.rc has license line:
# Distributed under the terms of the GNU General Public License v2
... and is used by the following ebuilds:
There are two options here -- either LICENSE in the ebuilds should be appended with GPL-2 to cover the init script, or the init script should be relicensed so that it is covered by current LICENSE (this one is probably the preferred resolution). See also bug 425702 .