Well, Foreman fought Frazier the same year and Jimmy Young the next year... and then he retired for 10 years, so I guess it answers your question. Since Foreman-Lyle was going back and forth, I think Foreman prefered fighting other opponents (like Frazier) rather than rematching Lyle.
I personally am convinced that Foreman-Lyle I took a lot out of Lyle, physically. After this bout, Lyle never seemed to have the legs that he had displayed in earlier bouts, including his excellent 1975 effort against Muhammad Ali. Thus, my guess is that Foreman would have knocked out Lyle in a rematch, and probably with less difficulty, too.
kenmore, good point. Foreman would have knocked Lyle out in a rematch inside of three. George also would not have been floored. The Foreman that fought Lyle was VERY ring rusty.
I think the Ali fight took a lot out of Foreman. After the Ali fight, the helter skelter old George Foreman was diminished. Foreman was more measured in his approach. This nearly cost him a defeat vs Lyle, and did cost him in a defeat vs Young. Foreman was a bully type, and those types have a harder time dealing with adveristy. Foreman retiring after the Jimmy Young fight could have been the best thing for him as he was in a spiral. Doubt is something no fighter wants to bring into the ring with him, and if Lyle and Foreman would have re-matched, I think Lyle chances for the upset would be very good because Foreman doubt levels were approaching their apex.
Their first fight was about it for Lyle and pretty much ruined him. His days of getting the ko's were gone and everything was decision bouts against the likes of Stan Ward/Bugner/Ledoux/ and then that bad Ball fight. Those A+ results were gone for Lyle and he was no spring chicken to come back from that brutal Foreman finish to their fight. That's one hell of a rebuilding project for the loser of that brawl & ronnie just never seemed to have that snap afterwards.
I wonder how a 35 George Foreman vs a 27 years old Ron Lyle would have looked like and then a rematch 2 years later ..