Yes, I suspect that although many manufacturers of physical gear are willing to license their names/logos for specific, limited periods of time, but not in perpetuity. Licensing also means a chunk of of IKM's revenue, so there may also be cases where there's no advantage in pursuing a licensing deal or its renewal.
I understand the attraction of official licensing: there are such a huge number of pieces of gear of different makes and ages, and how many people have heard Hendrix's own Marshall at full blast so that they could tell whether a model captured it adequately or no?
Licensing provides some reassurance in an age of "any programmer can skin any amp sim with a logo that vaguely implies Orange's", etc.
That said, I have over the years developed
reasonable confidence in IKM's modeling powers.
I know that the ENGL Powerball model was originally developed without any licensing deal and that ENGL came along later, liking it so well that the same model ended up with their official name and logo on it.
So I'm perfectly happy if new models that are simply "based on" come along, without manufacturer or artist endorsements, and I am not too bothered if originally licensed logos go away.