Legitimate-Bottle's journey

I recently applied for a position and my application is currently under review. However, I noticed that just 8 days after the original job listing was posted, it was refreshed with a longer title and new responsibilities added. I'm wondering if I should base my interview preparation on the original listing or the updated one. Is this a common occurrence? Did something go wrong with the original posting, or are they possibly consolidating roles? I’m feeling a bit uncertain about the situation and would appreciate any insights.