I guess that makes a lot of sense. The Nokia X is an Android device, so it would be difficult to port IE to it. They're not going to use Firefox or Chrome... they might potentially use a custom Webkit-based browser, but I'm sure Opera was more than happy to get their branding in front of a bunch of people.
Does the Android port of Opera still use the old Presto engine, or have they switched to Blink there too?
Android was the first platform to have a Chromium based release (and that was WebKit based, pre-fork!) with Opera 14 (no other platform has a version 14; all Chromium based Opera releases are just Chromium version minus 13, and nothing else shipped based on Chromium 27).