I think the last commercial aircraft I worked on that had tail plane de-icing was the HS Trident - none of the Boeings, L1011, or Airbus had it. The only reason I remember the Trident horizontal stab. De-icing is that the system incorporated a rubber flexible joint known to all and sundry as 'the Donkeys Dick'. Probably the most obscene looking aircraft component in history. The designer must have had a sense of humour.