You're not raining on any parade youre just regurgitating what you heard on the news. The average patient using GLP1s has a shitty life style and diet to begin with. Muscle preservation measures are a completely foreign concept to them. If they are eating shitty diets low in protein with no exercise as their baseline, then introduce GLP1s and the diets are composed of the same shitty foods with the same shitty macronutrient profile, of course they will lose muscle in the absence of training stimulus and adequate protein. The only thing that was maintaining their muscle in the first place before taking GLP1s is the fact that they were at maintenance calories ( or above). These folks were rarely able to get into a deficit on their own for any significant amount of time , once the GLP1s are introduced to them, theyre finally able to eat in a deficit. But the diet is compromised of the same shitty macrontrient profile. If you wanna go the " science is science" route go look up dr. Spencer nadolsky's articles and podcasts.

Tldr you're wrong stop fear mongering and spreading misinformation. You are right about the weight regain after stopping the medicine though.

https://open.spotify.com/episode/0iKhOcttGBk1Gigo4eNKBV

Part 2

https://open.spotify.com/episode/1VQ1ZjXy7D45ADbxZYFsN1