If I’m following this right, Tellem put Hari through an execution so that she could pull his oldest secrets out of him. Whoever gave him a body knew that holo-Harry would only make her put up her defenses and shit them out completely, but baing able to read a vulnerable (ie, biological) Hari would show her that he and the Foundation are not a threat, but her best chance to protect the Mentallics from Empire.

So probably she’ll pull him out and form an alliance, because she knows now that he does not wish them harm.