Yup, but it hasn't missed you. We no longer run Linux, but rather, Systemdix.
In Debian, systemd is inexorably replacing swathes of traditional *nix
functionality which we have over several decades learnt to use and rely
on. With Systemdix, we not only acquire a M$-style impenetrable
monolithic kitchen sink, but lose the interfaces with which we are
familiar.
My Debian 7.8 machine still has /etc/inittab, but the new 9.0 machine
doesn't. AIUI, though, it is not necessary to go back to the old
versions, as it is possible to replace systemd in stretch with a sysv package.
In fact, the first hit for "debian stretch sysvinit" is "Debian Stretch
- Without Systemd" Jackpot!
http://without-systemd.org/wiki/index.php/Debian_Stretch
Now, if that brings back ifconfig as well, I won't have to rummage about
finding which package that might be in.
It's fine to add new stuff to *nix, but the user interface for existing
stuff has to remain, or it's not worth a biscuit. (c.f. postfix, which
provides a sendmail-style interface for us old-timers.)