I understand you are just repeating Kawai's marketing stance...
I'm partly responsible for shaping Kawai's marketing stance, so my response is not altogether unexpected.
...but it is unfortunate.
Well, at least it doesn't stink any more.
There are $30 devices which have USB to host & USB to device capabilities and can do recording to MP3/WAV given an input.
No doubt there are, but those devices are probably produced in much larger quantities than any Kawai digital piano, and use 'off the shelf' components manufactured in even large quantities. I'm not an engineer, but I'm confident that if we could add 'USB to Device' functionality and MP3/WAV recording to the CN25 at just $30 extra, we'd already be doing it.
The other DP manufacturers all seem to recognize this with 2015 models.
The Kawai CN25 competes primarily with the Yamaha CLP-525, which does not feature 'USB to Device' functionality, nor MP3/WAV recording. Both models were announced in 2014.
Besides, Kawai cut the midi ports in adding the USB to Host...
I'm afraid you are mistaken. The CN25 features both MIDI IN/OUT connectors and a 'USB to Host' port - here's an illustration from page 40 of the owner's manual:
However, it's true that other manufactures have shown a tendency to remove the standard MIDI IN/OUT connectors when adding USB.