That's true, but I still test the rollback on all my liquibase change sets. This helps to ensure that I have a straightforward option to back out of my changes

That's true, but I still test the rollback on all my liquibase change sets. This helps to ensure that I have a straightforward option to back out of my changes solely in the case that something goes badly wrong immediately during deployment into the live environment. But I agree that any regression after that point requires independent consideration, for the reasons you give.