TBT is a great idea. Have previous coaches done this?
I don't think the coaches have anything to do with it. The TBT (The Basketball Tournament) is a summer tournament for former college players. I think this is the first time that a team of PSU alums has organized and participated in TBT. This team is called Happy Valley Hoopers. It seems that John Harrar is the main organizer for this year's team. If your former college doesn't have a team, I believe you're a free agent, and can participate on another team. Harrar was on the Purdue alumni team last year, and reportedly that experience motivated him to organize a PSU team.
I haven't focused too much on the Happy Valley Hoopers and TBT, so I can't vouch for every aspect of the above being correct. It's what I remember from various articles I skimmed through at the time it was announced that there would be a PSU alumni team in the 2023 TBT.