In fact, White House press secretary Karine Jean-Pierre won't even confirm that the meeting took place — even though due to Biden's own policy, the doctor's eight visits are public information.

"I'm not going to confirm a name," Jean-Pierre said during a tense exchange with CBS reporter Ed O'Keefe. "It doesn't matter even if it is in the log. I'm not going to do that from here."

It was probably related to this

https://www.parkinson.org/blog/awareness/national-plan

President Biden Signs Parkinson's Bill into Law

On July 2, President Biden signed the National Plan to End Parkinson’s Act into law. This is the first-ever federal legislation dedicated to ending Parkinson’s disease (PD).