When Opera ASA switched their desktop browser's rendering engine to Blink in 2012 - they were an Ads & Services company. 600M seems highly overpriced if all the consortium is getting is Opera's Blink based Android|Mac|Windows|Linux browser.
If and when Firefox completes its addon|extension overhaul to be "Chrome-compatible", it's quite possible we wont even have a single browser that allows the end-user to be in control.
Firefox still allows the end-user and extensions to change the page prior to rendering - which isn't as powerful as Opera 12 and its predecessors, it gives FAR FAR FAR more control than Blink based browsers allow.
It would seem this acquisition doesn't even include Presto - so that code base is thoroughly closed and dead.