Rupp's time is the fastest time run in the world in the last 8 1/2 years and is only 1.2 seconds off the fastest time ever run outside of the EPO era (mid 1990s to mid 2000s).
Ross Tucker says EPO use was "rampant in the sport" in the late 1990s and early 2000s:
https://sportsscientists.com/2017/05/recalibration-world-records-brief-thoughts/
Dr. Michael Joyner, writing in 2013: "There are about 50 people who have broken 27:00 for 10,000m, the fastest time since drug testing got “better” over the last 5 or so years is about 26:45. Many of the rest of the best times are from the mid-90s to about 2005 when epo was endemic."
http://www.drmichaeljoyner.com/how-believable-are-running-records/
If we throw out all performances during peak-EPO era between 1995 and 2006, the all-time list looks like this:
26:43.16 Kenenisa Bekele ETH 13.06.82 1 Bruxelles 16.09.2011
26:43.98 Lucas Rotich KEN 16.04.90 2 Bruxelles 16.09.2011
26:44.36 Galen Rupp USA 08.05.86 1 Eugene 30.05.2014
Not saying these three runners were clean, but these are the only three sub 26:46 performances outside the peak EPO era. Even Farah, Cheptegei, Kejelcha , and Kipruto haven't run as fast on the track as Rupp did.