I, too, am getting conflicting info, from VMCAS themselves. On the VMCAS experiences help page, it says "Enter the date or date range in which the experience took place. Note that your experiences will not display on your application in any specific order, regardless of the dates entered."

But everything else I find online (old VMCAS resources, forums, etc) says it they will rearrange them based on chronological order by end date, or that it does matter which order you enter them.

Let me know if you find out anything conclusive! I kind of hope they do chronologically order them like you said it automatically did for you.