The ebuild uses the flag to control installion of svg sources. However, packages rarely install any sources, so that's not a good reason for adding the bindist flag. As long as we distribute the sources along with the rest on Gentoo mirrors, things should be fine. I suggest renaming the flag to "source" (with appropriate local flag description) or "svg-source".
Thank you for reporting. Fixed in cvs and git. + + 02 Mar 2015; Johannes Huber <johu@gentoo.org> metadata.xml, + oxygen-icons-4.14.3.ebuild: + Rename USE flag bindist to sources, bug #541460. + https://github.com/gentoo/kde/commit/38440ec23922fabc838b374d63c1f3d1b61c58fe
