Github downloads are useless to the average user. It's a major violation to remove the previous 3.x builds. I hope no one else needs to upgrade a 3.x site cause it just got a lot harder.
I can confirm that the older versions will be back, just a small glitch at the moment. More on this will probably pop up in an announcement, or as reply in this thread.
Regards Robin
Board member, eZ Publish Community Project Board - Member of the share.ez.no team - Key values: Openness and Innovation.