citizens
vs
illegal immigrant

enough said?
..
due process:
abrego garcia went through the due process many years ago. but the deportation(plane ride) was delayed because of fears that he would be attacked by a (now defunct) rival gang

now that gang is defunct. there is no risk and the deportation procedure was able to continue

imagine it like getting a suspended sentence. where the sentence(in this case deportation) that had been given is stalled unless/until situations change.
the due process is done, but the person can still be punished at a later date if certain things occur

..
as for the feds court order to facilitate the return
well thats just paying for the taxi(plane), to ensure he gets back. thats not to invade el salvador or kidnap someone from their birth/naturalised country