Can the Jews reinstitute Temple service without the Ark of the Covenant?
The Jews can literally do anything they want because during the time of the Antichrist's rule, they will become so deceived that any and all compromises will be possible. Therefore, the Temple can be rebuilt and sacrificial services reinstituted without the Ark of the Covenant or the ashes of the red heifer. At this point, the majority of Jewish people are ready to do just about anything for the sake of peace, and when that moment comes, they will be all too happy to follow the deceptive dictates of the Antichrist. But illusion will end in a rude awakening in the midst of the Tribulation when the Antichrist sits in the Temple and declares that he is God.