At the moment, even with offline authorization contacting servers is required. Not only that... some time ago Sonar could revert to Demo without any changes in Windows/Hardware. There was something with badly set time-stamp, it has "expired" and had to be updated. That was "fixed", probably by updating that something, not by removing the "time bomb" completely. So there is far from zero probability that Sonar will work for limited time only, even when computer stay offline.
Till Gibson is declared bankrupt or selling CW, users are safe. Shutdown of authorization service is definitive violation of the license. If one of these two things happens, then...
But there was a promise about FAQ, lets wait it.