The Chinese SF fan community has been working on a bid for some years and announced their bid for 2023 several years ago. The more traditional Western SF community - WorldCon has been held exclusively in European or North American venues with the exception of Australia, New Zealand and Japan - was split over the idea, one faction feeling it was good to support SFF fans in China and create a more inclusive international SF community (and more convincingly put the "World" into "WorldCon,"), and another feeling that China should not be allowed to host a convention until its human rights record had improved considerably.
The WorldCon running this weekend - DisCon III, in Washington, DC - is where the decision on final site selection would be made. However, with Chinese supporting memberships for the WorldCon shooting up in preceding days and weeks, it saw a number of attempts to disallow ballots from being counted by changing the rules after the vote had been run. This attracting scathing opprobrium from SFF fandom commentators, who felt that whilst opposing Chinese human rights abuses and anti-democratic measures might be laudable, overturning WorldCon's own rules in the process and preventing a democratic vote by suppressing the numbers was not the right way to go about it.
Provisionally, these measures were in vain. China won the bid with 2,006 supporting votes compared to 807 for the other serious candidate, Winnipeg in Canada.
Barring further shenanigans, the 81st World Science Fiction Convention will be held in Chengdu, China from 23-29 August 2023. The convention's guests of honour will be Sergey Lukianenko, Robert Sawyer and Liu Cixin.