Turns out this is a bug (or, rather, missing bit) in debian-cd, not an installer bug. No archive changes required, just a respin after I've fixed the server side.
** Package changed: ubiquity (Ubuntu) => ubuntu-cdimage ** Changed in: ubuntu-cdimage Assignee: (unassigned) => Adam Conrad (adconrad) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1663299 Title: 16.04.2: `linux-signed-image-generic-hwe-16.04` is autoremovable after UEFI install To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-cdimage/+bug/1663299/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs