There is virtually no risk involved, that is why I said extract it to a temporary location, not restore, which sends it back to the original location. As I said it can't be checked whilst it is in the chest as it is a protected area.
If it were a good detection and active, having it in the original location would make it active again.
In a temporary location there is no associated registry entry or other possible file to run it, so in that temp location it is inert, provided you don't go trying to execute it and this won't happen by uploading it.
The updated virus database not detecting it would support this being an FP and that was what we were seeking to do by uploading it to VT, whilst it isn't essential the file could be submitted to avast only for analysis from the chest. But I prefer to conform before sending it for analysis and give the URL to the VT results in the report.
You can Restore it from the chest now, confirm it is back in the original location and you can remove the copy that remains in the chest.