I disagree. If you want to be the Champion of the World, you need the total package. You might win a GP event or even Medal at your Nationals, but you're not going to be on top of the Podium anywhere if you can't perform.
Look at Gracie Gold's INT scores at Worlds or Anna Pogorilaya. They are the epitomy of no expression. Judges unfortunately do not care that much as long as the jumps and spins are there. Good facial expression can help (Ashley eg) but won't hold you back if you do many other things well. The judges pretty much inflate the pcs scores if the technical scores are high. Evegenia Mevedeva gives about 15 seconds of facial expression at the beginning of her programs and then is mostly expressionless the rest of the time and no one seems to care.

She is something