Ob-Gyn questions? Ask a gynecologist online.
This is Dr Manos again. D&C findings in your case well after a csection is very rare. What's not rare is adhesions after one or more csections. Adhesion formation has been studied for decades and probably the one factor that seems to matter is the amount of time the csection takes. 15 minutes is good and fewer adhesions and 45 minutes longer with increased chances of adhesions. There is no answer to your specific question and adhesion formation.
Well that's another question and my opinion is yes it can invite adhesion formation. I believe I exteriorized about three times in over 4000 csections so I don't see the value of exteriorization. Lengthy papers have been written about adhesions and updates released by the American Congress of obstetricians and gynecologists.
I'm not one to ask that question to as I very rarely did that and I don't recall why I pulled the uterus out unless the incision in the uterus was a problem. Your question is beyond what I or Justanswer can discuss with you. Physicians who took care of you can answer.