Except they have. A Lufthansa spokesperson has clarified the new rules for the German news site watson: https://www.watson.de/leben/urlaub%20&%20freizeit/879935671-... It rougly translate to: The device itself is not banned, but has to be shut off during flight. In practice this would mean that you would have to remove the battery from the airtag, since there is no powerswitch. But I will admit that this seems odd an…
Don't expect for the service side of LH to turn their back on rejecting baggage because it has an airtag.