That's roughly the total COVID death toll for that period. The term "excess deaths" is used to refer to the deaths which occurred above the typical yearly mortality rate. In other words, the deaths which are roughly attributable to COVID.
I don't know if that's what you meant, but it would be easy to read your comment, given the context, as saying that Trump caused 522,368 deaths in 2020.
If you want to quantify the deaths caused by Trump's mismanagement, you'd need to compare COVID deaths relative to population. I actually managed to find that (to my surprise)
https://www.statista.com/statistics/1104709/coronavirus-deaths-worldwide-per-million-inhabitants/
If you sort by deaths per million (total), the US is 16th from the bottom right above Brazil, Slovenia, and Lithuania. And right below Latvia, Chile, and Poland.
You could also download that data set there, find the global average, sum up the difference between that and the US, and roughly say that number is the death toll for Trump's mismanagement.
Sniffed the onion