I was actually trying to imagine (no pun intended) how they'll pay tribute to the pandemic at the opening ceremony, and I thought they might play this song. Guess it's now been confirmed.
The second olympic cauldron at 夢の大橋 (Dream Bridge).
Looking at the shape of it, it seems like the pyramid structure in the stadium isn't actually the cauldron. Or maybe they have a different design for the second cauldron.