Perhaps I should have been more precise: I had set bicycle=yes (the legal stuff) and mtb=designated (the legal+ stuff). That was conflated into bicycle=designated. Nowhere on the ground I had seen either “signs” reading cycleway nor “design” that might imply a cycleway. Only just signs reading mountain-bike trail.
What do I mean with legal+? The path proposal says: designated as intended for a particular use, as opposed to such use merely being allowed. They high-jacked access tagging for tagging of intent. Not being a native English speaker, designated as intended might mean something completely different than signs or design, perhaps reading minds? The proposal pictures display signs, where designation comes in.