This was what apt did today, for anyone with clue following along:
Start-Date: 2019-03-19 10:31:42
Commandline: apt-get dist-upgrade
Install: pve-kernel-4.15.18-12-pve:amd64 (4.15.18-35, automatic)
Upgrade: zfs-initramfs:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo1), zfsutils-linux:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo1), spl:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo2), libzfs2linux:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo1), libzpool2linux:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo1), pve-kernel-4.15:amd64 (5.3-2, 5.3-3), libnvpair1linux:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo1), libuutil1linux:amd64 (0.7.12-pve1~bpo1, 0.7.13-pve1~bpo1)
Remove: insserv:amd64 (1.14.0-5.4+b1)
End-Date: 2019-03-19 10:32:27