We upgrade your application instances only on your request (and of course you must have a valid Atlassian license). If we upgraded your instance without your knowledge we could break some add-ons you are using, maybe something you have developed yourself or for which there isn't a version compatible with the lastest JIRA/Confluence/Stash/Bamboo/FishEye/Crucible.

We always try and do upgrades at whatever time is more convenient for you.