The integrated account migration / moving sounds interesting
That also exists in Mastodon (execution is slightly clunky but it’s there), so it’s not a ActivityPub limitation. Bluesky can also submit that protocol to become ActivityPub 2.0 or something.
The issue with activitypub is indemnity is tied to the username, so like when you move all threads will point to your old account. On AT other instance can update this internally and update their cached profile (I guess) I don’t fully understand AT
atproto.com
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