Pretty much. I watched those videos back when they were originally uploading, and they are really frank and candid.
A lot of these guys are used to the way big companies handle their PR. They talk big, make bold promises, and if the game falls short of expectations, they roll on to the next big, impressive project and go back to talking big and making bold promises on their next title.
The thing is, indie developers don't have that luxury. They can't let failed expectations roll off of their backs and move on to the next project, because there will literally be no next project if they fail to deliver on the current one.
Hello Games isn't owned by Sony. They are a 12 person team, who have been working on this game for four years. It is nearing completion, and they made sure to only talk about features that they'd realistically be able to implement in the game. Once the procedural algortihms were sorted out, they were able to grow the game out. Most of the features present in the game were talked about years ago, with the most recent revelations about the game revealed earlier this year (before E3), was that there were alien languages to learn by interacting with monoliths scattered throughout the galaxy. Other features like equipment/ship/armor upgrades were known ages ago.
An indie team can't afford to bullshit you. Their reputation depends on them being able to deliver what they promise. Sony, Microsoft, Nintendo, EA, Activision, etc, etc, can afford to lie to us all they want, because they more than likely have enough other cool looking projects to make us forgive a misstep or broken promise. Believe me, as a huge fan of the Fable series, I know all about the feel of smoke being blown up my ass.
Sean Murray and Hello Games can't afford to boast like a Carnival Barker. They can't afford to deceive and fool us by making claims they can't back. Because they know if they do, Hello Games' rep is ruined. That could have financial ramifications if word of broken promises spread and people don't purchase the game. Look at what happened to Lionhead. I loved the Fable games (Well, 1 was great, 2 was disappointing, 3 had fun co-op that me and my wife would play all of the time, but it still didn't capture the joy and charm of the first Fable), and where is Lionhead now? How is Molyneux regarded now?
People in the gaming industry aren't making games to get one over on you. They aren't setting out to make terrible, mediocre games. I know, because I work in the gaming industry. We do it because we have a love and passion for gaming, and want to make cool games that we, ourselves, would like to play as well. If Sean was guarded about No Man's Sky early on, it was because he didn't want to over-promise on a game he already knew his 12 person team would have to break themselves to pull off. He only revealed features when he knew they could do it and it was implemented successfully. If the game falls short, it certainly wasn't because they were trying to disappoint people or con them. Indy devs really can't risk their livelihoods on fucking over the fanbase.