Since diarrhea losses are unspecific, this doesn't help in managing the fluid overload as it can cause other imbalances

In fluid overload due to AKI, the management is specific; you need to only lose fluids, some patients with anuria may have low sodium or normal sodium, potassium and HCO4 the same way. And we need the calories to avoid hypoglycemia.

You may not because diarrhea causes loss of electrolytes, bicarbonate and nutrients through the gut.