is it easier to believe that one is silenced than to accept that one isn't that relevant anymore (to the general public)? This is not meant to be spiteful, it's just that most of the points above don't have anything to do with being silenced.
No record label - well, disputable how that came about
No management - because he doesn't want one?
No Airplay - where? The radio? And how if there aren't any albums out
No press support - he doesn't talk to the press
No releases since March 2020 - because he doesn't have a record label and refuses to self release (that would be a very artsy and punk thing to do and would suit his cause and roots that major record labels are not about real art and he has the resources)
No media interest in BOT and 40 years - again - he doesn't talk to the press.
You could add that there also luckily wasn't any major press coverage of him reposting David Vance.
He has isolated himself more and more for whatever reason and refuses to play the game that would get him all of the above. A major point is being out there not just at his own concerts or on his own website. Doing PR. He doesn't want that so it's a simple equation:
You don't talk to the press for years, you don't get your albums out, so you get no Airplay, you are no asset to a major label and the press/public just loses interest in you.
Sadly with this he can't have both. He can't be the super successful relevant popstar and don't go with the times. He doesn't have to but he craves it somehow.
He has a massive legacy he can be proud of so why doesn't he just put his work out there and maybe people outside the Morrissey bubble would listen again? He could do it on his own terms. But instead he believes he is being silenced. In my opinion the only one that silenced him is himself. Talk to people, get your work out there - be relevant or just be happy with what you have - a very dedicated fanbase.