2:06.07 in 2018 is 3:10 behind the WR.
Rupp's 10k is just over 1 second per lap slower than the WR. Just over 4s per mile. His 2:06:07 is just over 7s per mile slower than the WR. The 10k was when Rupp was at his break of running. I don't see him, at his age, getting much closer to the WR. Maybe a 2:05.x, but unlikely to better KK's American Record.