But atelier is already a perfect valid English word. Sure, it came from French, but it is now part of English language. Complaining about it would be like complaining that word 'Robot' is a Czech word for work/worker.
"... Display of superior knowledge is as great a vulgarity as display of superior wealth — greater indeed, inasmuch as knowledge should tend more definitely than wealth towards discretion and good manners. ..." [0]
Perfectly valid Adam, but clearer if you use a simpler non-romantic, common use replacement. The objective is to communicate, not impress.
I think the flawed assumption you're making here is that because the word is new to you the motivation behind the author using it is to impress. It's entirely possible that this is a word well known and in standard usage within the original target audience (which is not us)
"... It's entirely possible that this is a word well known and in standard usage within the original target audience (which is not us) ..."
'Us', isn't 'me' who does come from a fine/technical art background.
The distinction is subtle. If the writer means train artists with zeal then 'Atelier Method' would be the correct term but Atelier as a place to work? I would have thought "studio" would have been a better choice, derived from Italian, "studio" and Latin, "studium" (and "studere", to "study" & "zeal"). Note the French derivation, Atelier also translates to studio of "fashion designer" and "alchemist" or "wizard". This use is old and not used much.