Hi Lucy, this news it not really new. In their official terms you can read about it. If a writer makes less than $10 in a month, that pay will roll over to the next month until they amass at least $10. In the event that you quit or are removed from the Partner Program, Medium will disburse payment to you up to and through the date you are no longer in the Partner Program, regardless of the minimum payout threshold. However, they haven't applied this yet.

https://blog.medium.com/evolving-the-partner-program-2613708f9f3c