Assuming this is the case, they would technically not be allowed to file or PR something until it was a done deal. Or at the very least, you don't go blabbing about it until it's a done deal in most cases.
If there is a quiet period in effect, that would be one big reason.
Another reason might be that they're just still in talks and nothing is concrete.
I wouldn't expect them to PR a random, generic update. And I'm not sure it would do US any good either.