There are several possibilities: maybe it is a new RAW codec that is still under development.
Or, because it very much looks like a cut-price C300 Mark III, it is a paid firmware upgrade, like with some Sony and Panasonic cameras where if you don't use this feature, you don't have to pay for it.
It is quite funny how people said the C500 Mark II undervalued the C700, and then they said the same again about C300 Mark III versus the C500 Mark II
Unless there is a big catch somewhere, this camera may do the same yet again, with a much more flexible mount and the option of a Speed Booster for EF-mount lenses.