[newsgourmet]

"since covid19 causes some deaths that would not have happened historically"

That would not be a given assumption (under your scenario of zero excess deaths). Old people who would otherwise have died from another reason could die from Covid19 instead.

Or imagine testing everybody for the common cold, and if somebody dies with the common cold virus, they would be counted as a "common cold death". Then you would see a lot of deaths "from the common cold", without any actual change in death rates.