You can try it out with your own group/team and guid. It takes you to a landing page to confirm that you want to leave under a O365 banner. For the "join" version, I used the "invite others" link provided in the group settings page in People. This differs from add members since it's just a link instead of actually adding the member manually. On a whim, I replaced "join" in the URL with "leave" and since it took me a page specifically meant for leaving a group, my assumption is that it is indeed supported.
You can try it out with your own group/team and guid. It takes you to a landing page to confirm that you want to leave under a O365 banner. For the "join" version, I used the "invite others" link provided in the group settings page in People. This differs from add members since it's just a link instead of actually adding the member manually. On a whim, I replaced "join" in the URL with "leave" and since it took me a page specifically meant for leaving a group, my assumption is that it is indeed supported.
