lirc seems to be GPL-2+, not GPL-2. As-is, an issue is pointed out from license metadata when combined with a GPL-3+ thing, suggesting the result is a license violation, while in reality if it's GPL-2+, then the result would simple become GPL-3+. They can be used together in e.g media-sound/pulseaudio[lirc,gdbm] which would mean a license violation if lirc is truly gpl-2 only.
You're correct - the license of LIRC is GPLv2+
https://github.com/gentoo/gentoo/pull/4315/
commit 8e419c3f55ce8425a5f6b29168be91acb52a6c03 Author: Craig Andrews <candrews@integralblue.com> AuthorDate: Tue Mar 28 10:13:33 2017 -0400 Commit: Göktürk Yüksek <gokturk@gentoo.org> CommitDate: Tue Mar 28 18:10:45 2017 -0400 app-misc/lirc: Correctly set the license to GPLv2+ (was incorrectly set to GPLv2) Gentoo-bug: 614142