How would he have known about the future Reagan administration?
You speculate. Let's say that the current President Bush has to deal with a rabidly Rat Senate after this election, heaven forbid. Stevens croaks, he has to make an appointment. He tries a solid conservative, gets batted down. So---he finds a moderate, but a much older one, hoping that maybe in five or ten years his party gets control of the Senate again.
Hopefully, future Republican Presidents will have learned from Ford's mistake and act accordingly.