The Fidelity article is wrong. OK, technically it's not wrong, but it's very very misleading.
The Fidelity article clearly implies, by grouping that last bullet item which you quoted with the previous ones, that such a distribution would be a qualified medical expense. It isn't.
You *could* use HSA money to pay for the unsubsidized part of an ACA policy. However, it would not be a distribution for qualified medical expenses per the HSA rules in the instructions for Form 8889, so it would be subject to taxes and/or penalties depending on your age when you made the distribution.
I'm guessing that the author of the article and/or the editor aren't that familiar with tax law, or are simply confused. They might be confused because medical premiums paid out of pocket (including ACA unsubsidized premiums) *can be* included as medical expenses for purposes of Schedule A itemized deductions. But the HSA rules in this area are more restrictive, which is the part they seem to have missed.
Generally speaking, the better websites (and I would include Fidelity here) will be more accurate the the rest of the web (and AI answers) but they are sometimes inaccurate as in this case here. Often they are written in a very general tone which is appropriate for educational purposes.
Such articles usually also have a disclaimer that says that they're for general information and that you should consult your tax advisor and/or the IRS rules/regulations/instructions in all cases. This article has one at the bottom of the page.
