The Currency Revaluation permission with a minimum level required of Create, allows users to access the Revalue Open Currency Balance task. On the other hand, the Make Journal Entry permission does not have any effect on the user's ability to process a Currency Revaluation but will only control how the navigational path will show on the Center Tabs.
When Make Journal Entry = View then the default link will be Transactions > Financial > Currency Revaluations (which is the list mode). By going to the list mode, users will still have the New button if Currency Revaluation = Create (or higher). When Make Journal = Create (or higher) then the default link will be Transactions > Financial > Revalue Open Currency Balance (which is the transaction mode).