No, there was a judges order that he not be deported. The SCOTUS has clarified this point. He was not legally deported.
To this day, the Government has cited no basis in law for Abrego Garcia’s
warrantless arrest, his removal to El Salvador, or his con-
finement in a Salvadoran prison. Nor could it. The Gov-
ernment remains bound by an Immigration Judge’s 2019
order expressly prohibiting Abrego Garcia’s removal to El
Salvador because he faced a “clear probability of future per-
secution” there and “demonstrated that [El Salvador’s] au-
thorities were and would be unable or unwilling to protect
him.” App. to Application To Vacate Injunction 13a. The
Government has not challenged the validity of that order.