One thing i've seen a LOT of, is people in the replies to his tweets begging him to donate instead to charities, with scores of people underneath those comments saying that they will donate. With the amount of reach this has had I can easily imagine far more than 10k being raised for charities...
£10,000 is a relatively cheap advertising campaign. The awareness he has raised will raise far more money for many different charities than if he quietly donated that cash. people can’t see past what an individual could do with that money.