That is a very reductionist view and not particularly useful either. It shares elements with versioning and you could likely implement this using explicit versioning, but it is completely independent of it.
The main difference I see is that of focus here the focus is to migrate a database without downtime or excessive global locks, keeping multiple versions of the schema is a detail.
The main difference I see is that of focus here the focus is to migrate a database without downtime or excessive global locks, keeping multiple versions of the schema is a detail.