I hope for your sake that those two dudes knew what the hell they were doing. Being on different day - night cycle seems like a weird way of testing this feature.
Ok guys, since the whole two streamer thing seems to be something people use to argue for and against multi, let me clarify things:
The first stream:
1. I was there, in the streamer chat, of the first stream when they initially made contact with each other.
2. They both entered the same space station in the same system at the same time. They could not see each other's ships.
3. We figured that the space station must be a single player instance.
4. They decided to meet up on the planet instead but were unsure how to find the same spot.
5. One streamer renamed an outpost he had discovered to "booty booty" but the other couldn't find it.
6. They went back to the space station. Me and many others told them to fly in a straight line out of the space station since it was pointing right at the planet. They did so and as they entered atmosphere, came across an outpost that both of them could see.
7. They both landed at the outpost, which looked exactly the same, had the same name and the same NPC in it for both of them.
8. We then realized that for one of them it was day and for the other it was night.
9. We tried relogging them a couple times to sync up but it didn't work.
10. We then found out one of them hat a "strict NAT" or "NAT type 3" on PS4, which we figured would be a deal breaker anyway.
At this point, the first stream basically ended and I left.
The second stream started earlier today. I was not quite as involved in this one but I did see some of it:
1. They both managed to get their NAT type switched to "NAT type 2" on PS4, which is moderate.
2. One of them was "online" and connected to the No Man's Sky servers according to the menu, the other one was not.
3. One of them had PS+. the other did not, so he got himself a month.
4. They could not see each other and their time of day was again not syncd up.
I then left the stream to go to work.
Later I read that they eventually were both connected to the No Man's Sky servers, but again after relogging could not see each other at all.
I can not confirm whether this is true or not.
I hope this clarifies some things!!