I have raised the issue of this rant before and it gets mentioned frequently by Charles Shaar Murray in his various columns.
However, it was a long time ago, he was stoned at the time, he has expressed regret for it, he has worked with a large number of black musicians and gives credit and royalties to black musicians and heads a charitable trust which supports a largely black population.
On balance I think the Birmingham rant can be seen as a slightly shocking historical artifact and not the standard by which Mr Clapton should be judged these days.
He isn't doing anything new or interesting musically but I don't think he is pretending to and nor will people going to the concerts be expecting that. It is what it is.