I have updated my RPi 2 kernel towards "4.4.22-v7+" on my UbuntuMATE 16.04 OS and keep in the "/boot/cmdline.txt" file the same command line kernel entries
net.ifnames=0 biosdevname=0
and now when I reboot the box, I'm getting back again the former predictable LAN interface to be named as "enx..." when firing the command "ifconfig" 
Firing the "dmesg" command on the shell prompt, I find an entry as follows:
[ 7.685438] smsc95xx 1-1.1:1.0 enxb827ebf0d111: renamed from eth0
Thus, some kind of process is renaming the LAN interface during the OS startup.
Checking the post with title "Raspberry Pi 3 - eth0 wrongfully named 'enx…'" I'm not using any kind of "/etc/udev/rules.d/70-persistent-net.rules" rules to rename the persistant LAN interface - the file doesn't exist!
I went further and removed in the "/etc/iftab" a line entry that I assumed it is renaming the interface as described in the "This is progress? (iftab vs. udev)" article. However, no luck, after a reboot of the box, I'm still encountering myself with an interface name commencing with "enx..." instead of using the classic "eth0" name.
Since this did not help further, I examined the bug report "Predictable network interface names re-enabled after update on server image" and followed the instructions to comment out the line
ACTION=="add", SUBSYSTEM=="net", SUBSYSTEMS=="usb", NAME=="", ATTR{address}=="?[014589cd]:*", IMPORT{builtin}="net_id", NAME="$env{ID_NET_NAME_MAC}"
in the file "/lib/udev/rules.d/73-special-net-names.rules" (this file does exist, though).
Still no luck after another reboot of the box
Can anybody help here to point out what could have renamed the LAN interface name by the end?