We’ve seen it happen in some rare cases before, and different companies tend to handle updates for their Android devices differently. The situation can be particularly problematic with developers who frequently add various extra details to their software, such as modifications to the UI.
It certainly doesn’t help that these modifications are sometimes not accepted very well by the users themselves as they can cause certain interferences with the standard Android experience, even more when they conflict with specific features introduced in Android itself. That doesn’t happen often, but it can lead to delays in the development of Android patches. Whether or not this is the case here is hard to tell.
In the end, some users resort to an option that’s almost always available to them (depending on the specific device) – flashing a custom ROM. But as we’ve seen in the past, this has its own potential problems and is generally only recommended for tech-savvy users who know what they are doing and are willing to take the risk.
But if Sony don’t release Android 6.0 for the devices that they talked about previously anytime soon, this could lead to some issues for the manufacturer with their users, and could potentially cost them their reputation in the future. The company is in a relatively good position on the market right now, so that would be a pretty bad situation for them.