I have asked about this during Dev Office Hours and I'm waiting for a response from Staff to see if it's possible (at all) to have it enabled (after the migration).
I'll note, however, that many users expressed their disdain towards the Translate extension. I am not sure whether that is because multi-language wikis are generally hard to maintain (I imagine Extension:Translate at least tries to make it easier) and shouldn't be very common, or because Extension:Translate really does not provide a better experience in comparison to our current article translation mechanism. What I know is that the process of editing the base page while keeping it translatable looks pretty complicated from my (very short) experience on MediaWiki.org.