This upgrade will have significant effects on most phabricator users. We need a plan for how to alert people that these changes are coming, or at a minimum, that they have been deployed. All of the changes should be documented somewhere, possibly split by user-visible vs. internal/admin. I started a minimal list here: https://www.mediawiki.org/wiki/Phabricator/Feb_2016_Upgrade just as a starting point.
We should probably email to wmfall to try to alert staff, and wikitech-l. I'm not sure what other lists would be appropriate to try to reach anyone who uses phabricator a lot. Does phab itself support a tool to do a mass-alert to phab users?
I created this task so it could have an owner, and not get forgotten.