If you load the attachment and look at some of the mainland airfields in God's Eye, there are still aircraft present. On Fiery Cross Reef, even though there are no aircraft (all destroyed) you still don't get a damage assessment.
I think this is a bug that needs looking into.
My 2 cents...
The symbol of the black triangle on a yellow square would appear when a hosted unit is spotted but never disappears when an installation is auto-detectable. Even after dropping the contact.
You must be in view 'UNIT VIEW' (v / PgUp / Num 9) to see the BDAs of the grouped facilities.
Some air base installations (Runways, Space Tarmac, Open parking, Helipad, Weather Shelter ...) can not completely destroy.
They can take up to 99.9% damage, but never disappear. These installations are automatically repaired over time.(Light damage=1 to 19%damage / Medium damge=20 to 49%damage /Heavy damage= 50 to 99.9%damage)
When open facilities are damaged (Tarmac space, open parking), planes parked there are usually destroyed.
The last time aircraft were seen there is more than 6 hours (6h47,6h14 and 6:15), since they are not there:
whether in flight or moved elsewhere,
either your none of your unit can update this information.
But as you have a UAV flying over the area, either they are destroyed or they are elsewhere.
To all English teachers of the forum, sorry if English is not my mother language.