If all the fans stayed in the outside areas I believe transmission is a very (extremely) low risk. The problem is though that people will use concourses / toilets where transmission risk is much higher, and there is no way to stop people using this en masse in a large crowd.I’d really need to see more evidence about outdoor transmissions.
I watched a Panorama a few months ago that said you could have 80,000 in Old Trafford and have hardly any transmission. It’s the getting to and from the match that is the problem, in the pubs, on the trams/trains/buses etc. So if that was all true, I’ve no idea why this would need to be implemented at outdoors events. It would make more sense to just keep the pubs 'vaccine- only', but even then there's something that feels very Orwellian about it.
To try and be a bit light hearted, do we get our blue covid passports?