It's 'Export to validate' that causes it, not autosave.
We had a problem with autosaves meaning we could not accept them until Nadeo fixed them, which they now have. So autosaves are okay.
Export to validate was used by some players to get around the problem that we could not accept autosaves, but as we now can, nobody needs to use 'export to validate' anymore.
Note: In the games replay editor menu there is an option to simply 'Validate' a replay, you can use this on any replay file to 'check' it is genuine.