With the release of Commander's 2016 edition, we got a few very interesting things- including the Partner mechanic. We had a lot to discuss with this update, some rules to figure out and a bunch of things to decide.
One of the major decisions we came to early on in the format's creation was that we wouldn't support a four or five colour proxy general. With Partner's official release, we had to decide if and how it would be implemented.
Officially, we will support Partner, but there will be a special rule implemented for Tiny Leaders: "Partner commanders are only legal if their combined colour identities are less than four total colours". This ensures the original ideology of the format stays intact, while allowing you to play with this new and interesting set of commanders.
We will have an official rules update for you within the week. Have fun with Commander 2016!
-Tiny Leaders Rules Committee.