I disagree. Someone who is 60 or even 55 is not only close to the earliest age for collecting SS (62) and would have difficulty changing his plans so late, but that person may have already left his or her job as early as age 55, the age at which someone can begin withdrawing from his 401k upon job separation. Such a decision to leave one's job is probably irreversible. Using 55 as the latest age to keep the FRA unchanged not only addresses my concern there, but it will (by the time any measure would pass) address my other concern about not having one's FRA change twice after entering the workforce and paying FICA taxes.
1) This would not impact that many people in this situation and they are still eligible for a slew of other government benefits. Most people don't retire before 60 and most that do either can't work (and are on SSDI and not impacted) or could easily go back to work at the same or sometimes more money or are very well off and frankly won't be impacted by a few month delay
2) Most of those in that age range would only be impacted by a matter of months. Let's not over-state the pain they would have impacted. It's significantly less pain than a permanent 25% cut in benefits that's for certain.