My prediction on how different sized relays will play out:

mega relay = hot cache, short term storage for reliable realtime note retrieval, optimal for microblogging use cases. No guarantees for longterm storage.

edge relays = long term storage, private notes, note backups. Personal nodes. “Right to be forgotten” nodes. Custom use cases and products. Small communities.

Outbox/autopilot moves us from the niche microblogging usecase to a true large-scale nostr web. nostr:note1m6eargjah6dxvu4l8zxgrtf5jr4km6rzlerl0ztxw4aegqu2xszq5h5ea6