Apparently, 55 million die each year of all causes. So I wonder would that have nearly doubled the death rate or a subset of the exiting death rate? I read the article, but there is no mention. She did say that good distancing measures would/could "save" 38 million, so maybe she means that COVID fatalities would have been additive deaths? ?
Because COVID-19 is a novel virus (not seen before) when you see a number like that they generally are talking about new deaths. You are right to suspect there will be overlap in COVID deaths and people who would have died anyways and they can try to account for that roughly.
In reality, we will not know the real numbers for a couple of years. Researchers will use data from the years preceding and after the pandemic to model what a COVID-less 2020 would have looked like and compare to actual data to calculate what is known as "excess mortality." Doing those studies they might see something like lung cancer deaths dropped 50% in 2020 but rose back up to expected levels in 2021. Then they would determine if those people survived at a miraculous rate, or died due to COVID-19. Maybe 2021 deaths due to 'old age / natural causes' come in way below expected, and they could conclude that COVID-19 killed many in that demographic early.