It's right there in the article, if you'd read it:

Although AdBlock Plus states that "no one can buy their way onto the white list", it does charge fees for what it terms "support services", the details of which are not made public.

In February, the Financial Times reported that one unnamed media company had said it had been asked to pass on the equivalent of 30% of the extra revenues it would have made by having ads on its platform unblocked.

That has led some critics to claim that the Eyeo is engaged in a "racket".

If it truly happened, what's the harm in the company naming itself. They would have proof--emails or other communication from Adblock Plus.