Ok, so, I'm guessing it will be something similar like the clubs, teams, fleets, groups, etc, that I've seen in other games that I've played or you have played.
I'm guessing that you can have a private team where the creator will have to approve the requests from players to join in, or you can have a public team, where you can just join in, as long as there are still free spots on it, like in the pic above where it says open. And like @Abhi said, there will probably have an option to send requests to join in, if not right away, than later on when the teams feature works smoothly.
There have been games where I've played the team events & there have been games where I've completely ignored them. So, you can participate or not.
For me, the best thing about this for now is the fact that when you approve request from a player, you won't loose a material or ingredient, so I think everyone will participate & gain free materials/ingredients & I think that's great.
