A question to all atheists!

[Aoi Magi]

Also, OP, atheists might say "no" or "probably not" in regards to existence of god or deities because irrespective of the absurdity of those, their proponents have provided some testable claims as evidence( and which they keep rehashing from time to time) which can be used as a basis for forming opinions (all of those "evidences" however have failed and keeps failing hilariously in face of reality and scientific scrutiny), but in you entirely hypothetical scenario there is no testable property or claim to base an opinion on.