This tells nothing. Actually they could just run away with all that ETH they got now! Though they continue to work and keep promises. Even if you can't find them on LinkedIn or elsewhere, it means nothing. There are plenty of "legit" projects who run away after getting cash. Most likely these guys focus on things that matter and do not want anyone to disturb them. I must say, this is very high risk and very high reward project. So invest only what you can loose as always.