My best guess based on what they did with the FK8 refresh:
- standard Alcantara steering wheel (meh for me. I had to clean mine weekly on the FK8. It got old)
- newer head unit software with Google stuff built-in
- minor aero/styling changes
-broaden the operating range of the ADS system
The FK8 also got braking upgrades with the refresh, but the FL5 already has them. Realistically, I don't think there is much else for them to do. They aren't going to make major powertrain/suspension revisions.