I agree with you, @Julia Mihet.
It is not only malnourishment, but also misinformation about plant-based diet that causes ex-vegetarians or ex-vegans to eat animal products again.
I think of it as of other addictions and corresponding relapses.
You have to follow certain rules to not to become an easy victim of the meat and dairy industry, again.
If your body tells you "eat meat, your iron is low" it is not your body talking to you, but a choir of the voices of the old conditioned opinions and misinformations about nutrition and the usuals tricks of addictions who are talking to you.
Not your body.
Your body will take the iron of everything you eat, be it meat, be it iron-containing plants.
But you cannot eat ironfree food and expect to get iron.