I think the most important question is:
How many of your customers are making money with their Acorns?
If everyone is making money with it, maybe not too many will have problems with 80$ every year.
But if there are many hobbyists, without any yield from Acorn, i am afraid you won't keep much happy users with $80/year
I, as a hobbyist, wouldn't be willing (and able^^) to pay 80$ a year for my two Acorns. I am also sad, that my long-saved-Ultimate-license shall cost that much more for the upgrade. For me, that means i can't buy an Ultimate license again.
The Ultimate has just been a nerdy "got to have that" for me, as my lathe already had scales on it. Not needed, just "nice to have", and i saved up on it for some time, before i was able to invest such a sum only for my hobby.
And to be honest, if i would have to pay X-times 80$ to upgrade later, i would sell my Centroid stuff and get anothers company product for my machines, as this just is too much for me and only hobby. MY carbide-endmills cost around €2 a piece, the expensive and bigger ones around €20 and they are only very few

I would (and could) never buy endmills for $80 for my hobby?
And btw, i also would never buy a product on subscription-basis, jtm that once, too. I also don't know much people that think different about that? Maybe this is because of my hobbyist-bubble around me, but it's true, subscription-based-expenses just aren't really hobby-compatible in my opinion.
Most people, that asked me for more details about Centroid after reading my built-reports in german forums, were shocked when i told them the prices i paid. I am NOT SAYING Acorn/CNC12 wouldn't be worth it! But if you want to hear the whole and real story, then i have to tell you, that nearly all of that people (except one single person), bought other products for their machines in the end.
DIY-CNC is only a hobby for most people here in germany, as you would never get the permission to let employees work on a self-built-machine here. You can use such machines alone, even commercial if you want to, no problem because it's your own responsibility, but as soon as you have employees, many judicial duties must be followed, machines need certificates and verifications, so you won't find such machines in bigger companies here.
I don't want to be the bad guy here, i just think, you should hear the other side, too. Most people don't write contrary opinions down for not appearing confrontative, but just go away silently without ever saying what it was that bothered them.
As i said, no offense, just my 2cents on this topic.