As I've said, as far as the safety of the device itself is concerned, I would say that such a 'belt and braces' approach would always make total sense, and probably does so in a more general sense given its location on a ceiling.
However, whilst that remains true of the safety 'of the device itself', regardless of where it is located, if its location is such that its exposed metal parts could be potentially touched at the same time as touching something else 'live', then to 'unnecessarily' earth it would, at least theoretically, increase the risk of electric shocks due to some causes.
Kind Regards, John
