The official Comiket Twitter account announced that Comiket 99 will be postponed. This is due to situation surrounding COVID-19, which have resulted in an extended state of emergency in Japan. However, there are still plans to hold Comiket 99 within the year. The event is now tentatively planned for Winter 2021. [Thanks, Game Watch!]
The official statement goes into detail regarding the reason Comiket 99 has been postponed. The statement explains the current situation and why they have not outright canceled the event. It details that due to the high traffic at Comiket events, it would be the right decision to push the event back. This is due to restrictions placed on how many people can attend an event during the state of emergency. The event usually has roughly 200,000 guests attending daily, and a 10,000 guest limit would not be able to accommodate attendees.
Additionally, the official statement also asks attendees and vendors to refrain from making inquiries regarding other events to avoid confusion. At this time it is unclear how large the event will be in Winter 2021. More information will be released in the future through the official Comiket website and through the official Twitter.
Comiket 98 faced similar troubles in 2020. This was also caused by situations surrounding COVID-19, which led to the physical event being canceled. Instead, participants were able to view venues digitally.