Do you have an unobvious to the casual observer reason to prefer the oldest possible firmware image in the package? Intel is recommending certain firmwares with certain driver releases and following those recommendations one benefits from their testing and validation.
[ 2.329152] iwlwifi 0000:02:00.0: firmware: failed to load iwlwifi-7265D-13.ucode (-2)
[ 2.329158] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-7265D-13.ucode failed with error -2
[ 2.329175] iwlwifi 0000:02:00.0: firmware: failed to load iwlwifi-7265D-12.ucode (-2)
[ 2.329179] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-7265D-12.ucode failed with error -2
[ 2.329192] iwlwifi 0000:02:00.0: firmware: failed to load iwlwifi-7265D-11.ucode (-2)
[ 2.329196] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-7265D-11.ucode failed with error -2
[ 2.335448] iwlwifi 0000:02:00.0: firmware: direct-loading firmware iwlwifi-7265D-10.ucode
[ 2.335461] iwlwifi 0000:02:00.0: Firmware has old API version, expected v12 through v13, got v10.
Based on the table there and my dmesg output, the driver shipping in linux-image-amd64 4.1+67~bpo8+1 is LinuxCore 10 and the latest firmware currently shipping in firmware-iwlwifi 0.44~bpo8+1 is meant to be used with LinuxCore7.