The article brings up categorical perception when it says one shouldn't assume they are hearing sounds in another language correctly, since our brains will map those sounds to the nearest English equivalent.

What the article is really addressing is how different orthographic romanization systems map to English sounds. It's not advocating (as far as I can tell) that English speakers attempt to produce non-English sounds, which is, as you say, a difficult issue and probably not realistic without phonetic training.