Yes I buy that argument, it's solid. We just don't know how many Damus users use nostr as if it's a twitter, and a normie user might think it works the same; then one day wake up with all notes gone. Then think, "naw bad quality service."

Due to Damus being one of the largest onboarding to nostr, and it being one of the largest relays; I think at least on the first data purge a notification could be prudent.

The notification could even mention; "On free relays beware data may be purged, here's a backup option, and remember to post to more than one relay. The Damus relay, is purged next week on xDay. Expect no notifications in the future."