owncloud no longer in wheezy

[Sean Alexandre <sean@alexan.org>]

I see owncloud is no longer in wheezy, and I'm trying to understand why. Where
can I find information on why a package was pulled from a release?

I see this, but it only seems to say when it was pulled:
http://packages.qa.debian.org/o/owncloud.html

It was pulled from testing to unstable on 2013-05-14. I'd like to understand why, 
(and how this works in general.)

Is there somewhere else I can check?

I'm trying to understand the Debian development process as much as anything.

(I had installed owncloud on a wheezy box when wheezy was testing. I want to
install it again, but this time on wheezy stable.)