Portal Watch (2024) I'm not totally sure about this but I think Pepper did something similar prior to playing his final season. He declared for the NBA draft as a learning process to see what the NBA scouts would tell him about his possibilities in the draft and to give him advice about his game and his draft prospects. Evidently, he gained a lot of good information from the process and then committed to returning to the Aggies for his final year.
The difference here is that I don't think that Pepper ever formally entered the portal and TY has. However, seeing that TY has posted "I"M BACK," it gives me hope that he may declare for the draft like Pepper did and gain a lot of useful feedback from the scouts and then return to the Aggies for his final year. Got my fingers crossed!