I have a merge request to open-iscsi that would add iscsid/iscsiadm capability to initrd: https://salsa.debian.org/linux-blocks-team/open-iscsi/-/merge_requests/14
The default behavior is unaffected, so users would explicitly enable this feature if they want it. Using an iscsi root in initrd is of significant importance in cloud computing, and ensuring robust and reliable boot capability while using iscsi is best done with iscsid/iscsiadm and not iscsistart.