sounds like an attempt to just get more and more people locked in to a subscription plan.
Yes. You no longer get bug fixes or updates unless you are on subscription.
So if you buy the "perpetual license" (i.e. buy it outright, to use forever) and DON'T pay for subscription, then you are stuck with whatever crap version you get when you buy it. And it really is a crap-shoot as to what version you get. Some are stable and work well, others are just horrible and almost unusable.
It is no way to do business and keep your customers happy.
Altium are without a doubt, the most foolish business I have ever known, lost in pursuit of this years fantasy. They could OWN the entire PCB design market, from hobbist/student/maker through to professional. Yet they refuse to do the simple stuff required to do that, because they don't want to be just a PCB tool company, yet everything they do outside of the core PCB stuff fails, and fails miserably.
Not through lack of trying and good ideas though, some of their solutions outside of core PCB are excellent. They are just not practical to maintain and focus on for a PCB tool company.
Then they get into ridiculous stuff like rolling their own forum software which does not work, and all the Altium Live social media rubbish.
And they just continue to piss off almost every customer they have loyally built up over 25 years, including me. And I'm still one of their biggest supporters!

Dave.