As a general reminder, practice squad players are technically free agents. While they practice with a team, they are free to sign to the 53 man roster of any team in the league (with a few restrictions for upcoming opponents).
Dortch was a standout for the Jets in training camp and the preseason. He initially made the team’s 53 man roster but was waived when the Jets claimed Braxton Berrios. Berrios made Dortch redundant. The two have similar skillsets and would fill the same role. The fact the Jets still found a practice squad spot for Dortch suggests the team still saw something in him.
It’s a bit sad to see Dortch go after the way he flashed in preseason. On the other hand, it’s also nice to have players other teams want.