They will be cancelled eventually unfortunately. If not all athletes can be vaccinated how can the Olympics take place?
News reporting today that the Olympics are planning to go ahead in July this year in Tokyo. They have a "gameplan" that basically says no singing / chanting by spectators, masks to be worn outside of competition and yada yada. Apparently Tokyo has made great strides to get this the go ahead. If pubs are open and the Olympics are on it'll be great publicity for our boxers, depending on time differences, as we'll all be getting tanked up every day whilst they compete.
If the cancellation does happen; and no matter what the IOC suggest, there is still far from a zero chance it is cancelled, it has sort of happened before in 1980, via a boycott. Boxing, particularly in the US, had a bit of boon as the many talented fighters of that era turned pro. And the boycott helped the sport, as more fighters were given a chance, as they were not labelled as failures or successes, before their pro career had even begun.