No I honestly don't think it's a bad sign - I think the adcom just doesn't want to give away any hints on which way they are going to go on the notifications. So the better question is - Is there anyone out there who's still showing 'under review' that hasn't got an invite yet.
I'm sure the Adcom thought this through and i don't think they want to give an indication either way which is why they may have taken the notice done for ALL those still waiting. You can't lose hope yet, it's not over until you know for sure either way.