I would have random bouts of small cramping pain. They were much less than period pain, and I never had any bleeding along with them. They typically didn't last long, usually just a few hours to maybe a day at most. From what I've been told, your doctor gave you correct info. As organs shrink and atrophy, it often causes cramping.
I had a hysto as a prerequisite for bottom surgery when I was 14 months on T. I've had no issues since then. There is also a great Facebook group called FTM Hysterectomy where lots of guys have discussed their experiences, asked for/gotten advice, etc. I believe it is searchable, but if you want access and are unable to find it, let me know and I'll see if I can help.