Correct. At the moment the Nuki Box does not support a the Nuki Keypad.
What you can do is to use a Nuki Opener which in “other” operating mode in which it acts like a relay and can be used to actuate existing electric strikes (or locks). An Opener can be paired with a Nuki Keypad. If you need remote access to it you need to add a bridge (which needs wifi) somewhere nearby.
Basically it comes down to …
Remote access: Box comes with an integrated SIM card, Opener/Bridge Combo needs a WIFI nearby.
Access rights: Opener has same system as Smart Lock (i.e. one Admin adds and revokes keys/PIN codes). Box has more complex system where you can have one Superadmin (usually the property owner) and individual admins (usually a person living in a flat in the building), who can add and revoke keys on their own.
If you have wifi nearby and you do not want to pass admin rights along to anyone you should be fine with the Opener.
We do not comment about our roadmap here in the forum. At the moment it does not work and i would generally not advise to buy a product based on a feature that is currently not available but essential for you.