Kristin has two options for her clients.
Option one: The agency pays for everything except developmental editing. In this case, the author agrees to a term of liaison of 2 years. The author can still ask the agency to pull the book from any and every venue if for some reason they don't want to continue--they just can't republish it themselves until two years have passed. And the contract states that even though the agency paid for the cover art, copy-editing, etc, the author owns the digital files, and so has literally nothing to do to get upload-ready files.
Option two: The agency pays for nothing. In this case, the author can post the file wherever they want, whenever they want, and just upload their books to places the author can't reach on her own.
This is what I do. I do all the work and get 100% of everything from Amazon, B&N, and anywhere else I can upload myself. My agent uploads to Overdrive, so that my book is available to libraries and Google Plus and Ingrams. She uploaded a book to Kobo for me, back when you really couldn't get on Kobo through Smashwords and before KWL opened.
She gets 15% of the revenue from those venues where she uploads me and those venues only, and only for as long as I think it's worth my while to keep my books there. There is literally no term of liaison for option two. So this is not "15% for life"--it's 15% for only as long as it's worth my while to be on those venues.
I have no idea what Dystel is doing. It's already obvious that her exact implementation is different from Kristin's.