Upgraded... for now?

Hi,

I booked a PE ticked from Australia to the UK.

My Dubai to UK leg was upgraded for free to business. I believe they changed the plane to one without a PE cabin, hence the upgrade.

The upgrade says subject to further operational changes. Just wondering if anyone has experienced the same and knows what situations would take my upgrade away. Travelling business is not something I have done before and looking fwd to the experience.