It's not just that they're encouraged to eat food pyramid - the GLP-1 drugs make it extremely difficult to digest more than minimal fats and proteins. So you're stuck with eating very high carb food pyramid if you want to avoid puking all the time.

They aren't learning how to eat in a way that allows them to sustain the weight loss - they're only learning how to eat in a way that helps them avoid being constantly sick to their stomach on the drugs.

Then without the drugs in their system, the low nutrient, high carb way of eating means the appetite comes roaring back as soon as he drug wears off.

It comes back to what I've seen as a sig line on some posts on here (is it JEY's? I think it might be):

Do not 'go on a diet.' Start eating now, the way you are going to eat forever.

They can only eat such minimal amounts of food forever, if they take the drugs forever, and since insurance is in the business of paying for as little medical intervention as possible, they're going to cut you off at some point: either when you reach goal weight, or when you stop losing enough to warrant the expense.
'
If the patient on those drugs can't self-pay then they'll continue eating the way they lost the weight - only the brakes are off (no more GLP-1 being pumped into your system) and the appetite will be out of control.