As mentioned here Development week 40 update an FP3 OTA upgrade is to be expected after successful OTA upgrade function of the Samsung s8/s8+ models:
OS OTA upgrades
Status: 
Ongoing - release moved ahead to October
Completed
- Samsung s9 / s9+
- Samsung s7/ s7+
Upcomings
- Samsung s8 /s8+
- Pie to S OTA upgrade
- ETA October
- FP3
- Pie to Q OTA upgrade
- Q to R OTA upgrade
- To confirm if we can have a Pie to R upgrade
- Release dates would be after the s8/s8+ OS OTA upgrade (bold font added by me)