I'm not the original poster but I'll give my perspective on the question.
I'm 60 and still working at IBM and have been for 33 years. I could retire -- and work mainly because I want to -- but I've avoided (mostly by luck) a lot of pitfalls that can easily derail retirement. Here are some things than can easily prevent an IBMer from retiring before late 60s or early 70s: divorce, paying kids' undergraduate and graduate education, bad investments, layoffs and gaps between employment, buying a family home in 2007-2008, family health expenses, parental care expenses, being overly conservative with 401k, not having a defined pension from IBM, and on and on.
Now, add those pitfalls to the new reality of aging in 2018: pre-medicare health care costs minimum $15,000 / year for a 60 year old couple, almost no one has a liveable defined benefit pension, a $1m 401k nest egg really only generates (safely) about $40k / year (all taxable) income, social security is likely to be means tested soon and shouldn't be taken before age 68, medicare gap insurance is increasingly expensive, and so on.
So, as a general rule, I would say anyone under 70 -- even if s/he has enjoyed a long career with a single employer -- could still be very much at risk of needing to working late into life. It's not something any of us want to think about, but it's increasingly becoming the status quo.