I recently started experimenting with Mapbox Studio and have encountered some discrepancies between feature tags in OSM and the corresponding feature fields in the vector tiles from Mapbox Streets. The Mapbox Streets documentation for the roads layer states that the type field for most roads will be the value of the OSM highway tag. However, it appears that in OSM the following feature has the value 'path' for the highway tag while the attached image showing a query of the feature with the same id in the Mapbox Streets vector tiles shows it type value as 'piste' rather than 'path'. I encountered several instances of this that were giving me some unexpected styling results in one region.
How are OSM tags mapped to vector tile fields?