Some of our products do not have an intelligent display, so we have previously (6235 & 7260) used the LED output(s) as a basic user diagnostic to show that the WiFi card is present (fitted), powered and functional i.e. it is not in Airplane-Mode (Wireless-Disabled).
I am aware that this status information is available via the software interface, but this approach requires more intelligence and an extra pin from our embedded MCU to drive a status LED ourselves. It is nice and simple when the card does the work.
I have also subsequently noticed that Intel, appear, to have removed the hardware Wireless-Disable (Airplane-Mode) facility for the 8260. Again, I am aware that you can perform this function in software.
Considering that the M.2 (Key-A / Key-E) specification defines both LED outputs (LED1# & LED2#) and hardware Wireless-Disable (W_DIS1# & W_DIS2#) I was somewhat surprised that the 8260 didn't appear to implement it.
I was really looking for confirmation that the 8260 definitively doesn't support LED outputs and hardware Wireless-Disable facilities, just to eliminate any mistakes/misunderstandings from my implementation.
I am not sure what you are asking with your question "Is the adapter native to the system you observing the lack of these functions?".
The 8260 is plugged into a motherboard that has been designed and manufactured by ourselves. Over a number of years we have designed a range of embedded PC products, for which recent products have used Intel's 6235 and 7260 mini-PCIe cards.
This is our first design that uses an M.2 slot and hence the 8260.
[For information, this product also has a half-sized mini-PCIe slot. If we install a 7260 card into the mini-PCIe slot, then the LED outputs and Wireless-Disable functions work as expected.] [We do, of course, obtain additional certification for our products via approved testing using certified test-houses, compliant with CE-marking, e-marking and R&TTE directives, as applicable to each individual product].