For public files, I hope that there will be several organizations organizing multiple long-term pins of files.
Home users with enough bandwidth and storage. Existing CDNs. New cloud storage entrants (Backblaze).
Literally anyone with an internet connection and storage would be able to securely serve your content.
EDIT: I just saw your profile :) Thanks for the work you do at the IA!
For public files, I hope that there will be several organizations organizing multiple long-term pins of files.