Hi Valerie Kittell!
First, glad you are new here and engaged. Welcome!
Medium has published how they distribute the payment based on claps. Those quotes are direct from the Medium published guidelines and verbatim, plus the links to guidelines are included. The interactions I’ve had with them in the past, as well as current ongoing interactions, suggest this is exactly what they are doing.
What they say they are doing, supported by statistics, is evidence.
Sure, changes across the platform happen often. When they do we’ll all have to adapt as it suits us.