Delayed games are not always in serious trouble, but games in serious trouble are always delayed.
No Mans Sky have announced (before the date was due) that they are delaying the game, they've explained why (they want to polish it more). People have gone internet crazy about it but frankly I'm not concerned. It's happened once and they've communicated the delay, how long the delay will be for and why there's a delay. Two months is not a big deal.
Star Citizen has sailed past every date with no word from CIG, other than the chairman complaining that backers had the gall to expect him to keep his word. No communication about the delay, it's duration or why it was delayed. Just sulking by the man himself. The original release date was in 2014 that's two years ago, that's a big deal. The third version of the TOS has the latest delivery date for star citizen as midnight tonight a little over eight hours from where I am. Again no word from CIG that's a big deal. They just dropped out of E3 whilst saying they were far too busy, that's a big deal.
NMS is fine and thinking of quality, CIG is in full on panic mode (and if they're not they really should be).
I feel like maybe you're reading a lot into this, perhaps more than one should. "People have gone internet crazy about it but frankly I'm not concerned." could be applied to the discussion about SC, too. I think it's reasonable to expect that big games have dates that slip, it's nothing new in the industry. I also think it's fair to say that CIG are certainly providing more updates than a typical game studio does, to be sure.
I'm curious as to which specific missed dates you are talking about? If I recall correctly, the 2014 was an estimated delivery at the start of the campaign. It's reasonable that the estimated delivery date from the start of the campaign would slip. I know there was a graphic going around about dates in 2015, that would have put SQ42 out at the end of 2015 and commercial release in 2016, I think? I think that for such a big game, a delay of 6-12 months can be reasonable in some cases. I know Uncharted 4 and Mass Effect Andromeda both had release date slips of 6 months, and those are largely single-player games that are building off previous instalments. Blizzard is known for delays on its games. I think delays are rather to be expected on these type of games, don't you?
As far as pulling out of E3, I don't think it's that big of a deal. I mean, it's mostly a marketing event right? Wouldn't the detractors just say that they're wasting time at E3 instead of making the game? I haven't really seen any evidence that CIG is in "full on panic mode" or cause for them to be.
I do believe that was sarcasm. If SC ships feature complete in 7 hours and 18 minutes I will eat my entire hat collection and upload it to youtube.