I don’t think anyone’s disagreeing about the on-the-ground legal status of this path. Cycling is not allowed on it.

But I’ll repeat again: bicycle=dismount is documented as meaning that cycling is not allowed. It means the same thing as bicycle=no. It is appropriate tagging, but it reflects the signage and the fact that this way *is* part of NCN6 (as far as I can tell) better than having something tagged as bicycle=no in the middle of an NCN.

If this way is tagged as bicycle=no, someone who hasn’t been party to this discussion is going to come along and change the tagging again in future, based on seeing the ‘cyclists dismount’ sign.