Evidence is something to be discovered.You are asserting that absence of evidence is evidence of absence.
That would include everything that doesn't have evidence now or ever in human history.
Are you sure you wanna stick to that?
Can you discover something that existed long before you discovered it?
There's a difference between the definition of evidence, and whatever the word "evidence" refers to in use.
"Absence of evidence is evidence of absence."
Both uses of "evidence" here are references to data. Data exists independently of our knowledge of it.