The article mentions a ketone ester to be drunk, not necessarily (that I could tell) ketones derived from the broken-down-by-the-body-in-catabolism-amino acids...
Yes, by supplementing with ketones, you don’t have to catabolize muscle to get the ketogenic aminos that are used to make ketones.
An existing, well documented, alternative approach is to supplement with ketogenic aminos and let your liver make ketones.
I’m personally leery about drinking (or eating) ketones as there is a feedback mechanism in your body to prevent over production . Not sure if ketoacidosis could be caused by drinking ketones but it certainly is plausible.