results.
When executing a CREATE EVENT statement with ON COMPLETION NOT PRESERVE 
clause (explicit or implicit) and completion date in the past, we do not 
create the event. Or, put it differently, we create it and then drop 
immediately.
A warning is issued in this case, not an error -- we want to load 
successfully old database dumps, and such dumps may contain events
that are no longer valid.

Update the warning text to not imply an erroneous condition.