This is false. Medium has specifically stated that MPP is based on the number of members that clap (and highlight and respond) not the number of claps (or highlights and responses).

Anyway, don't fret about your confusion. You might enjoy my take on claps that I wrote when I was new too. https://medium.com/mind-talk/mediums-clap-system-amounts-to-a-vermiform-appendix-7587edb85a0a (note that was written when MPP was calculated solely on reading time)