I think the concert probably has to go ahead soon after the event. We are all still reeling from the horror of that night. But sadly memories are short, and I think that any fundraising that takes place too long after the event just wouldn't have the same impact. Awful to say - but leave it too long, and there will likely be another atrocity that will be the focus of public attention.
I don't like "slebs" being pilloried for wanting to take part. A pop/rock concert would be a bit of a flop without some pop/rock performers taking part. George Michael always used to take part in events like these - and let's not forget the news of all the quiet charitable acts he performed that only became news after his death. We don't know what "slebs" do behind the scenes so I don't think they should be belittled for offering their services. Yes they will get publicity for it, but they can't really perform incognito.
But as to the point of Jane10's OP - I am in complete agreement. Raising money "to help Manchester" is very vague, isn't it? Help Manchester how, exactly?
I don't want to seem heartless (although it's likely to come across this way), but how does the loss of a child impact financially on a family, other than funeral costs? I can understand the financial impact of an adult who is a main financial contributor to the family, but a child wouldn't have that contribution. No amount of money donated to a family that has suffered the unimaginable loss of a child is going to compensate them.
I do like the suggestions above that the money should be channelled towards counselling provision for those affected, because those services are grossly underfunded at the moment, or towards good quality prosthetic limbs if they are needed, or especially a multi faith/multi cultural park where children can come together in acceptance of each other.
I am all in favour of raising money to help in situations such as these, but I don't think it's unreasonable to know where the money is being aimed. Too often we hear about unscrupulous "top dogs" in the care of these funds, and one can't help but wonder how much is being creamed off in "administration" expenses.