Totally agree. Persistence is a huge part of what we usually mean by state. Nothing stops this from plugging into a real database when needed. But also, nothing stops us from rethinking what a database even is, especially in a world where LLMs have growing context windows and can carry more state internally. Maybe persistence doesn’t always have to mean "write to disk."
In the context of LLMs memory can often mean a broadly defined, application-specific ability to detect, retain and re-use bits of useful context along the journey. In contrast to Persistence which is more like a DB with a schema and clear expectations, reliability, etc.