So I checked it out today and now I am annoyed. From the east, everything looks as it's supposed to following the reroute. There's no sign of IN 28 west of 19. The truck route along Division Rd is also well signed, with "Truck" or "Trucks" tabs over the route markers, both on the route and approaching the junction along both 19 and 31. So, fine so far. One of the signs along the truck route was missing its auxiliary sign, but no worries, signage is hard. However, at the 28 westbound junction, all signage at the roundabouts shows 28 heading east and west from the interchange. The northbound exit sign on 31 is marked "28 WEST" but southbound it's just "28". And there's a lone 28 reassurance marker heading eastbound between the interchange and CR 560W, where INDOT's maintenance ends.
I did not travel north of Division Rd so I am assuming what was reported near Kokomo on aaroads (28 signed at IN 26's junctions with US 31 and IN 19) is correct.
I will reach out to INDOT's Greenfield district for information and make any needed changes based on what they tell me.