I would doubt it. And it's not uncommon for a JPA environment to keep records in application-level cache for performance reasons. It's one of the things that can help it out-perform raw
JDBC.
To maintain database integrity, there are certain checks made to ensure that some other app hasn't made asynchronous changes to data, and the strategy used to do those checks can be fine-tuned. But once data is committed to the database, it's not going to get deleted unless someone deletes it. Meaning either application code, external database operations, or, as I said, if you'd configured JPA to create and destroy the database when the application starts/stops.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.