The question of what makes a value a moral value is metaethical, not part of object-level ethics.

Sure. But any answer to that metaethical question which allows us to class some bases for comparison as moral values and others as merely values implicitly privileges a moral reference frame (or, rather, a set of such frames).

Beyond that, I don't see where you are going.

Where I was going is that you asked me a question here which I didn't understand clearly enough to be confident that my answer to it would share key assumptions with the question you meant to ask.

So I asked for clarification of your question.

Given your clarification, and using your terms the way I think you're using them, I would say that whether it's valid to class a moral change as moral progress is a metaethical question, and whatever answer one gives implicitly privileges a moral reference frame (or, rather, a set of such frames).

If you meant to ask me about my preferred metaethics, that's a more complicated question, but broadly speaking in this context I would say that I'm comfortable calling any way of preferentially sorting world-states with certain motivational characteristics a moral frame, but acknowledge that some moral frames are simply not available to minds like mine.

So, for example, is it moral progress to transition from a social norm that in-practice-encourages randomly killing fellow group members to a social norm that in-practice-discourages it? Yes, not only because I happen to adopt a moral frame in which randomly killing fellow group members is bad, but also because I happen to have a kind of mind that is predisposed to adopt such frames.