bxr.wiki and other Wikipedias without MessagesXx.php

Well, our pages explain how you can find TWN to translate here and tell you that at least the most-used msgs need to be translated before a new project can be approved. And if I remember correctly, the "threshold for the first creation of MessagesXx.php" is somewhere below full completion of the most used messages, so there was never a problem like this / such a problem should not further come into existence. Here, it indeed seems like the best to allow for exceptions from the threshold for existing Wikipedias which were created before the current requirements existed.