Here is the response from the support team:
The official answer is that we support Oracle 12c and therefore all features on 12c.
Since getting a firm response on this has been so inexplicably tiresome, I further drove home the point on the ticket by replying back with, "if CA/Automic support of "12c" implies official support for multi-tenancy and any other 12c features, then that's great." I haven't received anything back, and don't expect to, unless a point of clarification is forthcoming. In the case of no response back, I'll take my statement as sound, and a more direct affirmation of official multi-tenancy support.
Other customers won't be able to view my support ticket, but in case this subject comes up in some form down the road, you might have luck having the support team reference my case, #: 01075490.
Cheers!
EDIT: Even better, the support team doubled down on the confirmation. Much appreciated!
Just to confirm, we do mean that all features within 12c are supported which includes multi-tenancy.