While most standard ILS approaches do not support fully automated landings, modern aircraft like the FedEx 777F often have very advanced autopilot systems capable of handling the entire approach and flare, even without full autoland systems in place.
In your case, the aircraft may have been able to perform a near-autoland due to its advanced autopilot systems. Many newer aircraft can follow the localizer and glideslope precisely down to decision height and even perform a flare if the conditions are right, though a manual intervention is typically expected at or before decision height. Stick War Legacy
The ground lift effect may have also played a role in the soft landing, but the smooth touchdown could indeed have been due to the autopilot following through with the flare. If the autopilot was disengaged just before landing, it’s possible that it was the aircraft’s autopilot system doing the flare, not you.
In short, while KMEM's runway 27 does not have a CAT III ILS, your 777F’s advanced autopilot likely handled the flare, leading to a smooth, automated landing experience.