I've been trying to fix our preseed installs as well, and I found the preseed entry that works: (tested on xenial beta2)
d-i debian-installer/add-kernel-opts string net.ifnames=0 quiet splash elevator=noop
debconf-get-selections doesn't mention this parameter in the output, but is does work because dmesg confirms that the options are passed to the boot image:
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=123 ro net.ifnames=0 elevator=noop quiet splash
I've been trying to fix our preseed installs as well, and I found the preseed entry that works: (tested on xenial beta2)
d-i debian- installer/ add-kernel- opts string net.ifnames=0 quiet splash elevator=noop
debconf- get-selections doesn't mention this parameter in the output, but is does work because dmesg confirms that the options are passed to the boot image:
[ 0.000000] Command line: BOOT_IMAGE= /boot/vmlinuz- 4.4.0-18- generic root=UUID=123 ro net.ifnames=0 elevator=noop quiet splash