No it's a clarifying statement. I believe they're arguing that creativity is not depleted as a matter of biological inevitability - like decreasing skin elasti

No it's a clarifying statement. I believe they're arguing that creativity is not depleted as a matter of biological inevitability - like decreasing skin elasticity - but rather that older people tend to develop a mindset which doesn't correlate well with creative thought. Those are very different causes with very different implications.