
The answer is probably not, but it depends on how your report is structured. As long as the report is not filtering out the new parent project that you are moving the project to, you should be fine. Moving the project to another parent will not change the data inside that project unless you created workflow rules to do so (not likely). Testing on the Sandbox first is always a smart move--if everything checks out and no configurations changes have been made since the last Sandbox refresh, I think you are in the clear.