Perhaps she wasn't asked...
Were there messages from anyone who isn't UK based and reasonably accessible to the ITV cameras? And the inclusion of Olly Murs, Rhod Gilbert and Katherine Kelly didn't suggest that the producers were particularly concerned to stuff the show with his contemporaries or colleagues. After all, there was no Corbett or Forsyth, Tom Jones, Englebert or Petula Clark either. As a 'tribute' to Des, I found the whole thing rather disappointing.