Jonbwfc yeah. Apparently they convert to real saves at the end, according to the final milestone description (although it may be that I have to wait another four weeks until it ends globally).
I definitely didn’t have access to everything; not even the ability to build a base right until the last mission. That seems to have changed now though. The save is still classed as an expedition save but everything seems available to me.
One thing I was impressed by. The way they force you into the same area of the galaxy, really heightened the sense that the game is an mmo in some ways.
It feels very well populated in a way that never happens in the game normally.