Medicine cabinets are usually (always?) surface mounted. Below are a couple of photos of OP's Springdale, 2018 & 2016 models and show a med.cabinet above the vanity sink. Older models also appear to have a med. cabinet. No idea if these were original or added by the owner. Maybe the PO removed the cabinet and replaced it with a mirror?
Med. cabinets can also be added above the toilet (like ours). There's many sources of stock cabinets like Lowes, etc. If wanting something original looking and to match existing wood finish, may try a Keystone dealer and they could order one.