When you receive an Impending Drive Failure alert means that our machine learning algorithms have predicted, with a high probability, that your drive is most likely going to fail soon.
This alert doesn't mean that your drive is certainly going to fail. It has basically detected a similarity between your drive and other drives that have failed in the past.
You can either chose to ignore this alert or take precautions. For example, since you know that your drive might be failing soon, you can back up your data to avoid losing it, if and when the drive ceases to work.