Earlier quoted context omitted.
No, I don't think so. If the seller actually incurs monthly costs like hosting, this is absolutely fair. What I would call a dark pattern is when you buy an app, a piece of software that executes code on your device, and are forced to pay monthly fees. This gets more and more common. I understand the reasons, but I personally prefer one-off payments and buy software in this way. If it's good, I will pay for upgrades…
Why does hosting need to be bundled with software upgrade and support? Hint: It doesn’t.
It’s vastly easier, simpler and cheaper to support hosted software.