I had JUST used Android adb as superuser so I thought for some reason
adb faithfully recreated the folder structure, but after seeing the
contents of a mysterious /data/ folder appearing in my root, it
quickly became clear any accidental human error isn't mine (not
pointing fingers at anyone, let's make this clear):

root@nagirin:/home/riki# dpkg -S /data/etc/apt/apt.conf.d/05disable-suggests
devuan-baseconf: /data/etc/apt/apt.conf.d/05disable-suggests

Speaking of it, the contents of the file are:
> APT:Install-Suggests "0";
which should already be the hardcoded default in apt-get and aptitude?!