Unfortunately it's not clear from the article what else was being ingested... is it just high protein with little fat and carbs? Is it high protein with high fat and carbs? Have the mice been fed a sludge made of meat and sugar? Without those details, it's hard to judge whether this is relevant to people who are, for example, eating a high-fat diet that also happens to be high-protein, but has very little sugar. That they link high-protein to diabetes is a bit odd, for example, unless they're also giving a lot of sugar to these mice...
This study was actually of humans, not mice but I too am suspicious of the results. Unless they locked these humans up in a cage like a mouse for 20 years and then fed them specific and controlled diets, the results are dubious. Self regulated and self reported diets are notoriously inaccurate.
Unfortunately it's not clear from the article what else was being ingested... is it just high protein with little fat and carbs? Is it high protein with high fat and carbs? Have the mice been fed a sludge made of meat and sugar? Without those details, it's hard to judge whether this is relevant to people who are, for example, eating a high-fat diet that also happens to be high-protein, but has very little sugar. That they link high-protein to diabetes is a bit odd, for example, unless they're also giving a lot of sugar to these mice...