Etiquette policy <http://www.gentoo.org/proj/en/devrel/handbook/handbook.xml?part=3&chap=2>:
| Respect developers' coding preferences. Unnecessarily changing the
| syntax of an ebuild increases the load on the CVS server and can cause
| complications for others. Syntax changes should only be done if there is
| a real benefit, such as faster compilation, improved information for the
| end user, or compliance to Gentoo policies.
If you are not the maintainer, don't quote any policy compliance in
ChangeLog, I think this is a breach of the etiquette policy.