They say the new course is still spectator friendly and the elevation gain has lessened, but "only slightly."
Miller-Uibo’s time is the fastest time in the last four years.
"I have a strong chance of winning and I also have a strong chance of trying to break some records. I might not get another chance like this again because I plan to be doubling after this. The 100m is just one of those races where I'm not so strong in it that I know I'm going to come away with a win."
Gemechu took gold in 31:56.92 with her teammates Zeineba Yimer and Dera Dida right behind in 31:57.95 and 31:58.78.
Behind him, Rai Benjamin tied for the third fastest all-time with 46.98.
Sam Kendricks had a clutch clearance on his third attempt at 5.93m to beat Mondo Duplantis in the PV.