It would probably have been at a different time and under different circumstances but, sadly, I think it was inevitable.
I don't think it made a difference. Sooner or later he would have lost the title, stopped boxing, spent all his money, etc. Maybe getting hit in the head generally wasn't good for him. He shot his baby girl before shooting himself dead. It's really hard to fathom what deep-seated mental illness and despair would cause someone to do that.
I think Turpin had a lot of mental health issues that would have been there regardless. I don't think winning that fight and continuing a run on top really changes the circumstances around his demise much because even in a loss Turpin made good money and fame, he just made bad decisions and fell further into mental illness. I think it was all inevitable
Some say that Turpin had a low IQ and was barely literate but after hearing him speak publicly and also hearing the contents of a letter he wrote in 1964 I don't think that is apparent at all. Here is the excerpt from the letter which is clearly well-written: This content is protected
Like others have said, Turpin had underlying issues which probably would have surfaced anyway. Some people are just destined to self-destruct. Mike Tyson is another good example. It was always a question of when does it all fall apart.