It's not horrible, but it's not Stoicism either. The notion of eudaimonia (which is what you talk about) is found throughout the schools of thought of the Western classical world, and similar notions pop up all over the place in ancient philosophy, even in such places as India or China. Calling that "Stoicism" just leads to pointless misconceptions.

> The notion of eudaimonia (which is what you talk about)

That's not what's being talked about. Eudaimonia refers to the benefits of living virtuously, a core part of Stoicism, but not the part that's directly being discussed in this article. The ideas discussed in this article are about self-control, disconnecting your emotional well-being from things that are beyond your control, and seeking happiness from within. Those are quintessential Stoic principles. A lot of the modern pop-stoicism also delves into the benefits of virtue, maintaining the connection to eudaimonia and Socrates' question, albeit in a slightly round about way. The only Stoic principle that's usually left out of these discussions is pantheism.

> similar notions pop up all over the place in ancient philosophy

You're right, they do. That doesn't make them any less Stoic though. Perhaps if this was a Chinese message board, we'd all be talking about Buddhism instead. The two philosophies do have a lot in common.