According to NRL article below he asked for a release and it was granted
https://www.nrl.com/news/2018/09/12/manly-sea-eagles-young-gun-tom-wright-switches-to-act-brumbies/
Uncertainty over the 21-year-old's NRL pathway and best position in rugby league has played a part in his rugby league exit.
This was is why. When garbage like Suli, Parker, M Wright are chosen ahead of him. No wonder he asked for a release.