I commented the built in wireless that I don't use in /etc/config/wireless
It didn't show up in luci for a month. 
I rebooted and powered off and it stayed deleted.
I'm been trying to get a USB hub working, could that have brought back the builtin wifi device?
I had to recreate the AP.
Without the hub it is:
config wifi-device 'radio1'
option path 'scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb2/2-1/2-1:1.0'
With the hub it is:
config wifi-device 'radio0'
option path 'scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb2/2-1/2-1.4/2-1.4:1.0'
If I delete radio1 from /etc/config/wireless, radio0 doesn't work.
And I somehow got radio0.
Can it use
option macaddr '00:00:00:00:00:00`
instead of option path?