What happened to /boot/cmdline.txt?

I read the above several times to see if it answered the question.

Still I cannot find /boot/firmware/cmdline.txt

Maybe I'm missing something. So if I want to say, force fsck on boot or disable IPv6, where would I add that instruction?

Mine new install from this week shows:

mate@RPi2-mate:~$ ls -l /boot/cmdline.txt
lrwxrwxrwx 1 root root 26 Mär 24 2019 /boot/cmdline.txt -> /boot/firmware/cmdline.txt
mate@RPi2-mate:~$ cat /boot/firmware/cmdline.txt
cat: /boot/firmware/cmdline.txt: No such file or directory

Can I simply add instructions to /boot/firmware/cmdline.txt?