Yes, in some cases Cubase will automatically create a new input bus if you select your input via the hardware input option:
If this hardware input is already assigned to an input in audio connections (F4) Cubase will use the name that has been given to that input bus.
If this hardware input is not associated with an input in audio connections then Cubase will create a new input and name it after the hardware input itself.
One reason why you assign hardware inputs in advance under audio connections (F4) is that you can come up with meaningful names and that theses inputs will always be present in your mixer (no matter if you use them in your project or not). This way, you can create a dedicated setup.