This is from the interview CR did with GameStar.DE on Wednesday
"We were talking about showing a sequence last year, a section of the story that we were going to take to a finished level. And you know we're still basically doing that, we're in production on all of them and we'll be showing some things at some point. You know last year I said, "We are planning to show a piece of some Squadron 42 gameplay" and then we ended up not getting it to the point where we were happy with, but we didn't show it and everyone was very upset." - Chris Roberts
https://www.twitch.tv/videos/169412267?t=47m32s
What happened was they had a video of choreographed SQ42 gameplay (it was too unstable to show live and prone to crashing) but in the end CR was convinced to drop it from the presentation entirely. I expected this to have been fixed and stable and shown this year, or at the very least a video of it. The reasons for it being dropped from last year's show are subject to much speculation and vary from 'terrible dialogue' to 'embarrassing and cheesy'.
The release date for Squadron 42 Prelude was December 2016, when leaks of its delay (SQ42 delayed indefinitely) surfaced a few gaming sites ran press from CIG denying that it was delayed. Then it was pushed back to 2018.
Now - one of the reasons CR gives in that interview for the SQ42 delay is this:
"it's just a huge amount of high quality performance and motion capture data that we're bringing in and making sure that when the characters are moving around that they look really great and really fluid. I think it's going to be really great, it's going to be worth the wait let me put it that way"
Compare that to what Sean Tracy says in an ATV episode from June 9th 2016:
"SCENE MANAGER and ASSET MANAGER is basically a way within MAYA to take all our performance in basically two clicks... and you're within MAYA. It builds up all the characters, they've got all their weapon attachments, two clicks and it's OUT TO ENGINE"
Around the Verse: Episode 2.35 Jun 9, 2016 @ 16:20
So in June 2016 the mocap was out to engine in two clicks, in August 2017 it's (one) supposed reason for the delay in SQ42.
So you can take what's there and add a sprinkle of the leaks/rumous of the AI not working after 2 years and you can see what they're up against. And just for kicks, another snippet - this just in from Wednesday's interview:
" But no, you know I mean, I would say it's sort of the ANIMATIONS and the AI because we're going for a level of AI that you don't normally have so we want... ah... you know... when you're on, say... the ship you're serving on, at the beginning of the game it's the STANTON which is an IDRIS CORVETTE, you know all the crew have their full, you know... they have a SCHEDULE, they get up in the morning they EAT BREAKFAST, they go about their JOB, you know they go GET LUNCH, go back to their JOB...
... have CHIT-CHAT over DINNER, maybe UNWIND...
... then go back to SLEEP...
You know, there's a whole SCHEDULE and CYCLE and they're... so we... it's almost... like a level of sort of SIMS SIMULATION FOR THE AI" - Chris Roberts August 24 2017