This is a quite interesting study and it is, as you say, positive that at the end, there were not significant consequences to the mice. However, the malnutrition of these mice was only for 4 weeks, and it is well known that in acute malnutrition the principal parameter that gets affected it's weight and it can be reversed.
Sadly, in development countries the kids spend several months or even years, in malnutrition and not only the weight, but the height gets affected. They lack so many nutrients that also help to developt the brain, the inmune system, the hormones, among others, that the consequences are atrocious.
I'm in my last year of Medical School in Venezuela, and my thesis is about the comorbilities that kids with chronic malnutrition have, being one of the most common cause of hospitalization. Since they are inmunosuppressed, they are more susceptible to bacterial infections, parasitism and even virus like HIV.
These patients can receive all the antibiotics for their diseases, but if they don't get the necessary nutritients, their bodies won't be able to fight them.
This is our everyday in our hospital and is disheartening to see so many babies and young kids die because of this.
RE: What Are The Long Term Metabolic Effects Of Childhood Malnutrition?