I’m surprised you didn’t know about him… you just had to look up the Tokyo results on Wikipedia!
But seriously, I think his bronze was seen as a little random and not indicative of any sea change in athletics at the time. We Americans did not watch the ‘66 Commonwealth Games where Kenya went ham on the distance races, and Kiprugut got a silver in the 800. In 1968 there were Kenyans and Ethiopians medaling left and right but it was easy to chalk it up to the altitude. But then in 1972 those countries were prominent again in every distance final (other than our beloved 5,000 ironically) and Kenya and Ethiopia couldn’t be ignored. Kip Keino became the face of the whole explosion in part because of his big win over Ryun, but also because he won four medals altogether, including another gold in 1972, whereas Kiprugut and Naftali Temu (Kenya’s first GOLD medalist) had faded or retired by then, and Avenue Bikila, the first Ethiopian Olympic champion, was dead by 1973. Keino was present across the full spectrum of 1964-72 when Africans really started showing out, so he’s the one we remember best.