Update (00:00 UTC, 18 Jun 2017):

ESL Quake updated their statement about the region restriction rule and allowed African and Asian players in European Qualifiers, whereas players from Australia and Latin America will be able to play in North America Qualifiers. All players from mentioned regions must sign up again.

The Community Manager of ESL Quake, FoaMeA, announced in ESL Discord Server that qualifiers for Quake World Championship (QWC) will be available for USA, Canada and European based countries only. This means that for these qualifiers, players (or teams including players) from Asia/Africa/Australia/Latin America won't be able to play. Players from the mentioned regions have already been removed from the qualifiers.

It was also announced that the final version of rulebook will be availble at the beginning of the next week, with a clarification of round schedule, the exact qualifiers starting time, etc.

In the official announcement of QWC, Bethesda mentioned, that Non-EU/NA regions can participate in these Qualifiers with higher latency. NA includes the Americas and Australia, and EU Europe, Russia and Asia. At this moment it is unclear whether this restriction will apply to all qualifiers, or it will be removed after the appearance of servers in other locations.

Source: ESL Quake Discord