Foreword: I have translated a total of 27 articles from the JP-wiki onto the INT-wiki. None of them have been mirrored here, but might one day post them here. Maybe.
Imma be fully honest: I thought this was how translations already worked here lol. With that in mind, yeah, I think these are sensible points. A translation is pretty much a transformation of an already existing article, and so the original author should have a substantial amount of control over how the translation of their works 'translates' into other sites (At least this one, since that's the point), while the translator also keeps control because the transformative work (translation) still conferes them said control. The concept of co-authors works great here.
So yeah, I think the balance proposed here works. Both author and translation have the 'most' control depending on why a work is being deleted, and I think that creates a good balance that appeals to the different kind of relation author and translators have (Compared to normal co-authors, for example).
I don't think the policy makes it any harder to 'post' translations onto the wiki. I've never done this, of course, so I wouldn't know, but the posting doesn't really changes, especially as one doesn't really requires the explicit permission of an author to do so; this only matters at the time of deletion, which isn't really a common occurrence outside of standard deletions, so I think this change in policy can help address extraordinary cases where authorial intent and transformative work disagree without really hurting the influx of translation works.
So yeah, basically, I think this is a good policy that, again, I honestly already thought was a thing that existed.
