A
PR event by EY/QR is the most likely IMO but still highly unlikely inn the forseeable future. It may well happen for the 10th anniversary like EK did at GLA but that won't be until 2024 or 2025. Can't see AF bringing it for rugby charters, a bit over the top. Same re the shuttles.
Diversion purposes would be the most likely case of seeing an A380 at EDI, but there is more to accomodating it than having somewhere to park it.