Yep, for something to be validated it needs to be balanced, stable, and above all, static. No point validating something that changes every few days, since any change will break validation. So, as they're still in development, the BP and WoD multi packs just don't qualify yet.
The Port might, I suppose. I guess the main reason it isn't validated is that the team behind it hasn't decided it should be - Never forget that it's up to the mod teams themselves (or some officially-sanctioned volunteer, like bigchunk for the BP multi project) to get the ball rolling on something like this. Of course, there'd need to be a fair amount of testing to make sure it's warning-free and stable in multi, but that should certainly be doable should the Port team want to do it.