Latu entered the transfer portal last August after the fall camp depth chart began to emerge. I found this story about it:
https://kslsports.com/415220/hirkley-latu-byu-transfer-portal/?
"Coming out of Kahuku, Latu was 200 pounds and playing the safety position. During his career with the Cougars, he bulked to 240 pounds and was moved to outside linebacker then this past fall camp was moved to defensive end.
Last season, Latu was projected to see time at linebacker but he suffered a season-ending injury that sidelined him the entire year.
This past month, Latu had been competing in fall camp practices but according to sources was not in attendance at BYUâs final scrimmage of camp this past Wednesday."
It seems his body change/position change didn't serve him well and he was struggling to find time. Interesting he hasn't found another spot after a year.