The User Right Assignments you're specifying need to affect the computer objects in Active Directory, not your user object. In other words, the GPO linked to your "RemoteUsers" OU needs to be linked to the OU where the computer(s) your users are logging in.
Then, since your users are members of the
Everyone group, they'll be able to connect remotely, as long as Remote Desktop is enabled on the target computers (e.g. by enabling it directly on the machine or enabling the
Computer/Administrative Templates/Windows Components/Remote Desktop Services/Remote Desktop Session Host/Allow users to connect remotely using Remote Desktop Services group policy setting).
A Better Way to Grant Remote Desktop Rights
Modifying the default User Right Assignment security settings is a less preferred method of granting users the right to use Remote Desktop, particularly because URA group policies are not cumulative. Instead, the URA specified in the last GPO which is applied "wins," overwriting previously applied GPOs. This makes management of these policies difficult on anything but a small scale.
A better approach is to use a Group Policy Preference to add the target user or group to the computer's Remote Desktop Users group (which is granted the required URA by default). For more information, refer to this Microsoft TechNet blog post.