There is very little motive for Penrith to release him for 2021. They get nothing out of it basically. He is contracted, he is a good lad so he isn't going to do a Barba or Klemmer and start crying to force their hand. If Cleary or Luai go down for the season Burton can potentially ensure that they barely feel the loss. The only reason Penrith would let him go is out of goodwill. I know we've let players go early, but we can't expect other teams to reciprocate just because it suits us.
We can absolutely hold it against them though, what goes around comes around. Play nice, and things are great, fail to show goodwill, you won't get any coming back your way.