Earlier quoted context omitted.
Maybe not (who knows), but the relevant aircraft transport regulations apply to all types of lithium-based batteries.
Not really. 2032's power most watches. There are far more watches than air tags. Why didn't they ban them?
They (Lufthansa) didn’t ban AirTags. When asked about whether AirTags are allowed in checked luggage, they cited the pertinent ICAO regulations. They might do the same when asked about powered-on watches with lithium batteries in checked luggage.