Missed
The US was reporting roughly 25,000-35,000 new confirmed COVID-19 cases per day at the end of April 2020 — about a million cumulative cases by April 28 — not 'close to zero'. The pandemic went on to kill over a million Americans, making this one of Musk's most cited failed predictions. CDC MMWR — COVID-19 case surveillance, US, Jan-May 2020 (cases still in the tens of thousands per day at end of April) ↗
The 'probably close to zero new cases in US too by end of April' tweet of March 19, 2020 came two weeks after Musk's 'the coronavirus panic is dumb' post, as US lockdowns were just beginning. Instead of approaching zero, daily new US cases were around 30,000 at the end of April 2020 and the US passed one million cumulative cases that week. It remains the most iconic of Musk's COVID-era predictions.
Missed
Cancelled
Pending