That was because Lucas thought people might get confused between Anakin Skywalker and Anakin Solo.
We know now that was not true. It's complete bullshit made up by the editors of the NJO series to cover their own asses. He had thought the original idea for NJO of Anakin Solo fulfilling a prophecy to defeat the Vong ala PT was not very original idea and that was it. The rest of it from ordering the death of Anakin or Jacen as the hero was all on the shoulders of the editors.