It's not about MSport dropping out, it's MSport being precluded from competing and also the other UK residents who would work on the event potentially being unable to travel.
Yeah - I see. at first read it seems that it was more about M-Sport not attending, rather than the personnel.
Toyota Gazoo Racing Europe museum and collection in Köln: https://www.youtube.com/watch?v=HgiKciAyj5Q
Rally Museums around the globe