The games should be cancelled. The IOC is at serious risk of losing its credibility and the support from the TOP programme, local sponsors and broadcasters. What would happen if there is a games-time outbreak in Japan? What if the games are held safely but a few days after the OG finish, some athletes, officials or journalists test positive and face complications with Covid? (as we all know, if the virus sneaks into the respiratory system, you can consider geniuinely screwed) The biggest scandal associated with the IOC and the OG could be igniting, impacting Beijing 2022, and probably Paris 2024.
We all know it´s all about the cancellation / force majeure clauses within contracts with sponsors and broadcasters. It´s probably the most complicated decision in Sports in decades but the so called "celebration of triumph agains the virus" could turn into a global fifth wave".
Proposal (the obvious one): Paris 2024, LA 2028, Tokyo 2032
Host cities and years cannot be swapped out. Apart from the direct revenues the IOC receives (sustaining NOC), you cannot tell the staff at restaurants, or hotels expecting thousands of visitors in Paris that the games will be postponed to 2032 in order to reschedule Tokyo to 2024.
It would be insane not to award the games in 2032 to Tokyo. In case games are held this Summer, I would also award 2032 games to Tokyo, as in 2021 Tokyo will be hosting an event which goes ahead to secure contracts and longstanding deals.