Is it better to have a stud come through the program than not? Of course. But all these people talking about "will always be associated with BYU and have BYU mentioned throughout a HoF NBA career" seem to overestimate how much people talk about which college players attended.
For another example, consider Anthony Edwards. He was a clear #1 prospect, went to a non-blue-blood school (not Kentucky, Duke, North Carolina, Kansas, even UConn, UCLA or lesser "basketball" schools like Arizona).
He was a #1 recruit, was the #1 draft pick, and has blossomed into an NBA star. And how often when talking about him do you really hear NBA announcers mention his college?
Will it help with recruits and inside the program? Of course. But I think we're overestimating the impact of one player, even an elite one.