From what I've read, I thought we would have a scale of multiple solar systems, but given budget and time this either won't happen in a timely manner, or at all. It might not have been in design at all.
A fusion of ideas from another thread presents a seasons or league system in which everyone plays on a single planet at a time, moving on to the next when it's completely terraformed.
When humanity first lands on a planet they first establish a few major Biodomes, T1 collection and terraforming facilities that double as colonies. From there, players move out into the Badlands/Wasteland/Wild with MEK-As to begin harvesting resources for the dual purpose of improving their own equipment and contributing to the terraforming effort. As the colonies grow, T2 collection points called Depots are constructed. These could be world events, or player/company erected structures. The construction of depots, and subsequently T3 collection Outposts enables a wider area to be efficiently mined, the idea being that while you can technically call a MEK-A anywhere, it still has to walk back to the nearest collection point.