Just so you know, the 200 device limit appears to be per location, not per hub. So you would have to add a hub with a different location. It can be in the same physical building, but in the app it will be a different location. The 200 limit applies to virtual devices, as well, and you can hit it even if you don’t have a hub at all.
People have been asking about this since the first (unannounced) limit was hit, and I don’t think there’s ever been an official response. One staff member did say that they were discussing raising the limit, but I don’t think that person works at smartthings anymore.
Anyway, there are several threads discussing it: