We always have the cleared Runway ( for the correct Airfield !! ) selected in our FM/FMC for all arrivals and update it as required under the circumstances/clearance. It only takes a few quick keystrokes to clean up the Legs/Flt plan page.
For one thing this ensures that waypoints sequence correctly in case of a missed approach, yes a visual approach may not necessarily follow the published missed approach chart but until you clear it up with ATC it's a starting point.
Not only that you'll get an accurate distance to touchdown and most likely a 3deg glide path indication as well depending on setup. All helping your situational awareness picture in the circuit area.
Use what you've got at all times to get the job done safely and prevent those Swiss Cheese holes lining up...
I never said the FMS *couldn't* be made to do the right thing. In this case, either it *wasn't* or neither pilot was paying attention, intent as they were on the visual. Will your FMS display the extended centerline without any cleanup if you're navigating to an IAF at the time you're cleared for the visual?