Well, licensed sports games don't have that freedom or luxury because they are licensed by the specific sports organizations who want control over their image in the digital world. No sports organization is going to want there game with "tasteless" aspects of the sport. Madden fans have had to go through this for over a decade now with concussions, late hits and tattoos removed. The NFL just opened up about having tats back in the game recently too.
But also, most fighters don't actually get that opportunity because there is a ref to stop them. When I looked at and posted two YouTube clips that showed most of 2017s KOs (nearly all the clean KOs most likely since it was a
Best Of compilation), there were only about 3 or maybe 4 clean KOs where the fighter was even able to go off throwing more than one extra punch. The rest were mostly TKO situations like we still have in UFC 3, we just need a few more maybe. Then clean KOs where the fighter walked off or waited for the ref actually happened more than the excessive followups.
EA MMA did not have hits after the KO either, but it wasn't noticeable because the fights ended smoothly and you still had plenty of knock downs that ended with follow ups still. I'm only really concerned about ref interaction since that's what will make these finishes completely realistic. Because imo, a ref just sitting back allowing multiple follow ups and just ending a fight instantly w/o a ref getting inbetween are both immersive breaking elements to me. For now, just make the transition from KO to ending the fight not so abrupt so we can actually enjoy the KO still. Then hopefully they can get a ref to interact with the finishes down the line.