Oh wait, this seems to happen for all netboots (at least currently) :( I think it's because of the think I mentioned in comment #10: the busybox ip command does not support the valid_lft flag, and the kernel sets the IFA_F_PERMANENT flag on any address without a lifetime, and then subiquity assumes it was manually assigned vs arriving via DHCP.
Oh wait, this seems to happen for all netboots (at least currently) :( I think it's because of the think I mentioned in comment #10: the busybox ip command does not support the valid_lft flag, and the kernel sets the IFA_F_PERMANENT flag on any address without a lifetime, and then subiquity assumes it was manually assigned vs arriving via DHCP.