Early US Deaths in Years Ending in Zero

Sometimes a census record is all we have to indicate that an ancestor lived until a certain point in time and that enumeration is often used as a “last alive on” date. Whenever I see an unsourced death date of 1800, 1810, etc. for an ancestor in an online tree or any reference, I wonder:

did someone enter his death date as “after 1800” and did someone (or their software) strip the “after” from that date?

Several genealogists indicate that a relative died in 1800–no source. The last census in which he is recorded is 1800. While I don’t use these unsourced dates of death in my own records, I still wonder if there is any credence to the year of death they have. Did they find something that I have overlooked?

But when the year ends in a “0,” I really wonder if the “after” got stripped from the approximate date of death.