It is most likely a security setting that turns these on by default. A document containing tracked revisions could be hiding information that the author doesn't want other people to see so the security settings make sure there are no hidden surprises in your documents.

Go to your options Trust Center and in the Privacy Options area look at the setting that says 'Make hidden markup visible when opening or saving". Is this turned on? If you turn it off, does it change the behaviour you are complaining about?

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Andrew Lockton
Chrysalis Design, Melbourne Australia