This doesn't necessarily mean that any user could pick up and switch to a different PG instance, as such a young provider maybe look at having some docs for migrating off-platform as a sort of assurance. Maintaining those docs might also help you prevent adding or changing things that would introduce lock-in, it should be a consideration for every feature or API change.
Agree. We will prioritize how to migrate from Nile. At the Postgres level we don't want any lock-ins. We would have APIs that simply SaaS workflows that users may choose to use.