As we have more or less made Github PRs and community involvement via Github standard practice, I think it would be advisable to add all new developers to the Gentoo organization on Github as part of their post-quiz, pre-announce devhood process. On a related note, it might be advisable to just fire off an email to whichever ML is most appropriate to make sure existing devs are aware of the organization, and to give them a vehicle to request membership if they do not have so already.
https://wiki.gentoo.org/index.php?title=Project%3ARecruiters&type=revision&diff=414804&oldid=382810