You're absolutely right. In this case, it means that an append-only data store with a fixed retention time might be a perfectly reasonable way to store certain

You're absolutely right. In this case, it means that an append-only data store with a fixed retention time might be a perfectly reasonable way to store certain kinds of records. This means that an append-only data store is not guaranteed to run up against deletion requirements in all cases. In my opinion, this is particularly salient and worth being aware of when the conversation centers around a financial company, data storage, GDPR, and deletion requirements. It is possibly not always likely to be as simple as "use append-only" or "append-only likely to be illegal".