Yes, it would indeed be very interesting to know the excuse.

From the time Emirates was first established, they were always determined to be seen as a professional operation, one that would steer well clear of this sort of tacky practice - ie messing 'normal passengers' around in order to please a particular individual deemed to be more 'important'.

Way back in the very early days of Gulf Air, fare-paying, fully-confirmed pax would frequently be re-routed or even denied boarding so that one or other of the minor royals + hangers-on (ie those not quite senior enough to make use of the private fleet) could be flown at short notice on a shopping spree. Eventually GF sensed that they were becoming something of a laughing stock in the business world, and realised this had to stop once & for all.

We don't know the full facts in this case and my analogy may or may not be relevant ; but shifting folk from their booked seat can be a dangerous game to play in terms of the wider damage that results from the affected passenger relating his/her unwelcome experience to other EK customers - AND potential customers ........