No, that would make it possible to create alternative instances to use if and when the main instance goes belly-up. Those alternative instances would start afresh, without the user base and lacking any content created by them. If there were more than one alternative instance the two would not communicate unless they employed some sort of federation - ActivityPub or something similar - or some mirroring scheme.
Got it! This is an important distinction - open data not just open source. (But throwing back to another recent thread - I think this is at odds with privacy - data can't be both private and persistent beyond the existence of a single server.)
