Wow, that's impressive! Even in my most robust save my sims only occupy 3 of the worlds we have available to us. You've filled up 206+ lots? That's... pretty dang incredible. That's a lot of work! If you don't own all the packs, there is an awesome sale going on within Origin that would let you pick up some worlds for a huge discount.
If you haven't built anything on it, yet, you could always use freebuild cheats to build on the lot in sylvan glade or on the landing pad in Sixam. I can't remember if it allows you to change the lot distinction, though, it has been a very long time since I have edited those lots.
In answer to your original question, though, there has been no word or hint of them adding new lots, and I don't expect them to.