How the flu can help us determine some broad trends for the route of TAR15:
All destinations in East and Southeast Asia are taking substantial measures to contact-trace passengers who arrive on flights with infected persons, and quarantine is a distinct possibility. Containment measures are drastically more relaxed in South America, Europe and Africa, so we should be seeing TAR15 take a West-to-East approach, where the risk of sharing a flight with an infected person into Asia is lower.
Africa, East Europe, South and Southwest Asia are up until now relatively untouched by the pandemic - not surprising, given the comparative traffic volume from North America. We should be seeing some of our destinations come from these regions.
Osaka and Melbourne are fighting community spread, with significant clusters across the rest of their respective countries. China has a very strict containment and quarantine policy, and a history of under-reporting the severity of contagious disease. Hong Kong has just declared its first case of community spread. If TAR15 decides to go around the world, I see Southeast Asia as the most plausible Pacific crossing point.