I recall several indoor 2-miles in the late 70s that were run in the 8:20s on similar type tracks. Those athletes did not have Rupp’s 5K PR, so I would expect to see Rupp in the 8: teens even on the Millrose track. Also, if the field ends up as is, this is not great opportunity to chase times for LV; I would imagine if Rupp is in the teens, the other guys will be the 20s and LV would be well behind the pack at perhaps an 8:45 pace, which is not too shabby.
Btw, a healthy GF is an athlete I would not underestimate; I would not be surprised to see him running sever meter behind Fam or nipping at Rupp’s heels. Keep in mind that Fernandez ran a 3:55 mile and 7:47 3k two years ago.