It also does this, which I find extremely weird... After installing, apt reports:
The following packages were automatically installed and are no longer required:
acl apache2-utils auth-client-config bind9 bind9utils ldb-tools libapr1
libaprutil1 libauthen-krb5-easy-perl libbasicobjects0 libc-ares2
libclamav-client-perl libcollection2 libdata-hexdumper-perl libdhash1
libfile-libmagic-perl libini-config3 libipa-hbac0 libkdc2-heimdal libldb1
libnet-dns-perl libnet-ntp-perl libnl-route-3-200 libnss-sss libntdb1
libpam-pwquality libpam-sss libparse-recdescent-perl libpath-utils1
libpwquality-common libpwquality1 libpython2.7 libquota-perl libref-array1
libsamba-perl libsss-idmap0 libsys-filesystem-perl libtalloc2 libtdb1
libtevent0 libuuid-perl libwbclient0 libxs-object-magic-perl python-crypto
python-dnspython python-ldb python-ntdb python-samba python-sss
python-talloc python-tdb quota rsync samba samba-common samba-common-bin
samba-dsdb-modules samba-libs samba-vfs-modules sssd sssd-ad sssd-ad-common
sssd-common sssd-ipa sssd-krb5 sssd-krb5-common sssd-ldap sssd-proxy
sssd-tools tdb-tools update-inetd zentyal-dns zentyal-ntp
Do *NOT* run autoremove!