There was a discussion about this even yesterday and it may happen at some point but couple of limitations:
- no server - implicates necessity to issue different client (with arrival engine)
- progress have to be different - like separate “offline account”
- limited content (not same amount of planes/liveries)
- offline version would be “cheaters paradise” - we will not hide the fact that online one is our priority becase we can control what is going on.
Finaly - online needs content to arrive on regular basis as playerbase is still growing. I would not expect that fast anyway.