Note that if you are in the demographic of well educated and high income Americans, your life expectancy is still quite high and you should assume you will live to your 90s when planning for retirement!
The decrease in life expectancy observed is being largely driven by people on the middle to lower portion of the income spectrum. It's very unfortunate that it is happening and so many people are struggling. Hopefully our country can come up with solutions to help out people who are struggling with addiction and poor health.
But, it's important to remember that if you are not in that demographic, you are still likely to live a very long life and need to plan for that.