licensing/authorization change?

Yes, there was such change... Also note that since some Z3TA2 update, it also has that "feature" (was quite bad surprise for me).
 
But they still do not "count" authorizations and offline authorization is possible (some computer must be in the internet). I do not know any precedents when some company went out of business without giving permanent authorization to existing users, owners can get much more problems with lawyers in such case compare to the "simple" bankrupt scenario. As the last resort, if the software is good, it does not take long till some "nice people" disable its protection...
 

Well, if a company goes bankrupt (or sometimes even is sold), it is pretty common that whatever assets they have goes to their successors, who are not typically required to continue to support their products even to the extent of re-authorizing whatever protection schemes they have in place for old products to the former customers of the defunct company. In some cases it does not even require that much disruption to lose access to old software. Microsoft Office 2000 still exists in my hope chest on a CD that I can install, but no longer update to the version current when it went out of support, since MS no longer provides the update files. The SP1 for that product was only available as a stub loader, that no longer connects to anything anywhere, and Microsoft Update does not work on it. So if your software depends on any action on the part of the company that made it, you should pray for its ongoing success and future good health and generosity. In an era when so much is tied to encryption or online reauthorization, even if you are promised a perpetual license there is little you can do if circumstances change. Trying to take a defunct company to court to enforce your contract will put you at the end of  a very long line of abandoned litigants. Modern software is like beer, you only rent it.