I'm not sure I believe ASS about RGG forbidding them to release earlier. DXV claims to have no knowledge of that, and the only reason to frobid it would be a shortage of metal tokens.
It's possible there's a miscommunication. Maybe they are just not struggling to be clear, and in their minds "RGG won't let us do it earlier" is their way of saying "RGG didn't give us the files until this date."
RGG may totally have effectively limited how soon other versions can come out, by when they get the files. RGG used to send out the files earlier, and there were leaks, and so the files don't go out as early. And then they need translating and maybe you reasonably don't feel like scheduling the printer when you don't have the files yet. So that would delay other versions relative to English. It wouldn't mean some other imposed release date delay though.
RGG may have put some other imposed release date delay on other publishers; you could ask RGG yourself. I have never heard of such a thing myself, but I'm not actively trying to find out everything there is to know about these interactions. The only times I've known of RGG limiting the release date (beyond the files thing which for sure delays people), it's been to not be *ahead* of the English version.
Man I hate talking about this stuff now.
RGG is doing whatever, ask them if you want to know, don't bring me into it.