I went down to KDAB once VFR on top and got cleared for the RNAV when I asked for the ASR. /P the whole time. I swear they just assume you're RNAV capable.
Fun fact: DAB still has an ASR listed as an available approach, but you'll never get it. DAB has said they're not manned to support it, since it takes a dedicated controller. "People" have said they've engaged the FAA to remove the listing, but I'm not convinced anyone has actually done that.