They should be considered canon but should be ignored at all costs. They only should be mentioned when people bring up the fall of Anakin, rise of The Empire, The Clone Wars etc. Not only that but certain things need to be retconned from the PT so that the collective story of Star Wars flows well. They can kill the original Boba Fett and have someone take his identity, they can retcon Midichlorians and they can get Hayden the hell out of Return of The Jedi. Unfortunately they can’t do anything about Padme or Cliegg Lars dying from broken hearts.