"Best" schools (<1%) will have what the article is describing (strong student mathematical problem solving communities lead by teachers with strong mathematical training). Typically very expensive, either directly through tuition or indirectly because they are public schools but only serve students in very high net worth zip codes.
"Very Good" schools (<10%) will include some of the epsilon-delta formalism but might have some curricular problems and a "gifted just means moving through the terrible not-real-math curriculum faster" problem that the article talks about.
"Decent" schools will teach how to compute derivative/integrals by rote and maybe talk a bit about the physical intuitions in a very hand-wavy way. Calculus is very much a continuation of Algebra or Trig where you learn some rules and how to pattern match and don't ask too many questions about why.
The other half of USA high schools? They don't even offer a Calculus course of any kind [1]. Which... if you don't teach it at all, you can't teach it wrong...
As an aside, AP CS has the same problem as the problem identified with AP Calc. AP CS is the epitome of a "Java School" course.
[1] https://www.theatlantic.com/education/archive/2016/06/where-...