Clinically, HFLC diets are used for non-WLS gastrectomy patients who need to avoid weight loss and ultimately regain unwanted loss and indeed, this does present one of the challenges for WLS patients who adopt this approach. During the early weight loss months (when we are relatively insensitive to diet due to the enforced restriction courtesy of our WLS,) many will proudly proclaim that they "do full fat everything". This works fine when we are largely consuming "condiment" amounts of fats early on, but often bites people when they carry that practice into maintenance and allow the higher calories to get away from them. It can be done for whatever reason you may want to do it, but you do need to be watchful of your overall consumption to avoid regain.
Philosophically, in the absence of a specific medical condition that warrants it, I'm not a big fan of diets that are "low" or "high" of anything as that implies deficiency or excess. One might do a short term very high or low diet to counter an existing imbalance (such as treating insulin resistance with a very low carb diet,) and then moderating that extreme to a more balanced state as the body's chemistry corrects itself for the long term.