First, let's assume that they used a 60/40 portfolio, where half of their equities were in VTSMX (U.S. stocks) and half in VGTSX (international equities), and the bonds were in VBMFX (total U.S. bond market). Let's also assume that their starting portfolio was $1M. Their withdrawals occur at year end (first year withdrawal of $41,355 on 12/31/2000).

As of 12/31/2017, the inflation-adjusted value of the portfolio would have been $670,363. Their last year's withdrawal would have been $58,626. This means that they have about 11.4 years of withdrawals left, assuming a 0% real return going forward. So as long as these retirees get a small real return on their remaining portfolio, they shouldn't have a problem making it to the 30 year milestone typically used in safe withdrawal rate research.
What if they had gone with a more conservative portfolio like 40/60? Their portfolio would now be worth an inflation-adjusted $748,413.
What if they had gone exclusively with U.S. equities and had no international exposure (60 U.S. equities/40 U.S. bonds)? Their portfolio would now be worth an inflation-adjusted $702,401.
Anything could happen going forward, but it looks as though retirees who rigidly followed the '4% rule' will make it to the 30 year milestone. That being said, their portfolio would have dropped to an inflation-adjusted $532,570 in Feb., 2009. The portfolio recovered to $684,815 by the end of 2009, but it still would have been difficult to withdraw that year's spending of $49,965, 7.3% of the remaining portfolio, only 10 years into their retirement.
NOTE: I mistakenly adjusted for inflation twice in the above numbers, which are overly pessimistic. The retirees would have had a nominal balance at the end of 2017 of $982,518, about 16.75 years of spending assuming 0% real growth going forward. So they could 'guarantee' success by buying enough TIPS to cover the next 12 years of spending, ensuring that they make it to the 30 year mark.