Definetly this is not a Multiplayer game.
You will never see nor speak not chat with another player.
You will only be able to see (if online) taht a planet for instance has been visited as long as previous player gaves names to things and planet.

But there is nothing about 'meeting' or 'seeing' other player.
It IS a single player game in a shared universe, in some way.
Once-for-all.

The multiplayer is about leaving your mark by naming planets, flora and fauna.

No chat functionality in the game so how you communicate with folk would be reliant of 3rd party stuff like discord etc.

I don't think there's any models for the player character so those would have to be added.

Closer to the core the higher the chances of finding the same planet but on PS4 folk did this and weren't able to see each other.

The game isnt an always online universe like elite dangerous the only time it really needs a connection is to upload planetary info.

Oh and you can pause the game to go for afk, just imagine how annoying that would be if the galaxy stopped just because wee jimmy had to go to his grans and left the game paused.