Qualifying at Worlds would be difficult - not impossible, just difficult - because the ISU only hands out 16 pairs spots at Worlds (the rest are for Nebelhorn). But those 16 spots include the multi-spot countries - so, say, if China gets three spots, 16-3 = 13, there are thirteen spots to share between the rest of the countries. And so on. So I think if Katia and Harley want to qualify at Worlds, they'll need a top-ten finish, probably. Maybe higher than that. We don't know an exact number yet.
Gosh okay. Quite the challenge! But thanks for this info!