I'm an AWS Solutions Architect and I was helping a customer with the same issue as in the article a couple of months ago.

What I found out when I researched it is that there is a subtle difference between using lifecycles to move objects to other storage classes and for deleting objects: deletions are not transitions, they are expirations – and expirations are free. I submitted a clarification to the S3 documentation and now it says "You are not charged for expiration or the storage time associated with an object that has expired." (https://docs.aws.amazon.com/AmazonS3/latest/userguide/lifecy...)

If you have objects in IA or Glacier there is a minimum duration you're charged for, but there will be no extra charges for expiring these objects.