This means that people aged 52, 53, 54 or 55, who have planned their entire careers and their retirements according to known standards and rules, will see their entire futures turned topsy turvey.
Cela veut dire que les gens qui ont 52, 53, 54, 55 ans, qui ont planifié toute leur carrière et leur retraite en fonction de normes et de règles connues, verront tout leur avenir bouleversé.