No, Coutts haven't made a statement. People are inferring it's due tot he wealth level as this is explained on their website. Farage hasn't denied this.
He was offered a Natwest account as a replacement, he wasn't left with no bank account.
If we were still covered by EU regulations, banks can't remove a customer without offering them the basic pay in / pay out bank account. Sadly, Mr Farage was very influential in removing us from the EU. So, you know, karma sucks.