Yes, Rupp is a 2:09 guy and is not a (hypothetical) 2:05/2:04 whatever guy because 2:09 is his PR. Obviously!
But:
1) Time is absolutely NOT an objective basis to compare athletes at different races. This is just plain dumb.
2) A race without pacers will not produce a fast time, unless:
a) There is 1 athlete that is at least an order of magnitude better than everyone else and so the pacing strategy doesn't matter (e.g., Leonard Patrick Komen in Healthy Kidney 2011)
b) There are multiple top athletes that are approximately equal, but at least 1 of these athletes is the type to push the pace without consideration for strategy (e.g., Ryan Hall in Boston 2011/Pre in any race)
3) Rupp absolutely crushed the last 10k at Chicago against top athletes (Kirui, Kipyego, Lemma) and won easily. He is a 2:09 guy, but it's ridiculous to think that an athlete with a 2:09 max potential would be able to do 1:06/1:03 with the last 10k in the 4:30s.
4) Rupp has not had a bad marathon and has thus far only been beaten by Kipchoge, G. Kirui, and Lilesa. At some point, you have to admit that at least some of these 2:04/2:05 guys didn't lose to Rupp by chance.
5) Rupp has fully transitioned away from the track and is now solely focused on the marathon. Expect great things!
6) We don't know how Rupp will do in a rabbited race. He could very well be a guy that performs superbly in championship races, but falls flat in paced races (e.g., Stephen Kiprotich). To be considered a top marathoner, Rupp needs to be successful in both championship and rabbited races.