"Confirmation"? No, just just other tabloids repeating the story. I'm hoping it's not true, but... It's not a choice that sits well with an attempt to lure younger viewers, or transatlantic ones - my suspicion would be that if there's truth in it, he'll be a recurring regular like Camille Coduri, Bernard Cribbins or Matt Lucas, rather than the main everyday travelling companion.
Bradley Walsh would certainly fit into a Wilf-type character, but at this point if his casting is accurate it could mean practically anything. I'm still hoping we get to have a companion not from contemporary earth, or maybe not even human. We haven't seen a non-Earth humanoid mainstream companion since Turlough!