seems like there's alot of BS surrounding this case :)
well, I thought Dr M's answer was spot-on, but perhaps there's 2 different issues here. One is practical diagnostics and the other risk stratification. The actual diagnosis can't take place post op until normoglycemia is established. Some facilities screen up front by taking HbA1Cs of all patients- this is optimal, but expensive. So the practical treatment is to wait for a rescreen- even if the patient is prediabetic, there is no practical urgent treatment window (circa 3 mo.) to be filled.
that being said, I think your point about risk stratification is better preventative medicine. So, an entire screen should be done to look for secondary markers:
1- does the patient have other symptoms?- polydypsia, polyuria
2- family history of type 2?
3- recent (bellyfat) weight gain?
If a patient's preop screen captures these markers, then I think that your proactive referral is indicated. If no secondary markers, then again there is no practical diagnostic or treatment needed in this case. And of course the reductio ad absurdum is that if all post trauma hyperglycemic patients were referred for prediabetes risk, the community would become the clinic :)