Both, upstream version and Debian version already have the following change:

commit 988e967513fc9dc2be35dcb5bbc6b888f853538f
Author: Douglas Gilbert <email address hidden>
Date:   Wed May 11 17:20:52 2016

    rescan-scsi-bus.sh + 55-scsi-sg3_id.rules: fixes from HR at Suse
    
    git-svn-id: svn://localhost/trunk@703 6180dd3e-e324-4e3e-922d-17de1ae2f315

which fix the SERIAL issue (but not the delay in insertion caused by errors of sg_inq commands). 

That will be enough for this particular case (MAAS related). I can, during the next merge (F-series) propose to upstream a change not to execute sg_inq 0x83 if 0x80 wasn't successful, but, for now, taking in consideration the phase we are for Eoan (almost freeze), I'll base the changes in the upstream commit (at least the changes for 55-scsi-sg3_id.rules changes).

Marking F-series and Eoan as "Fix Released" as they keep the serial like it should be:

rafaeldtinoco@lenovo:~/work/sources/ubuntu$ sudo udevadm test -a -p /sys/block/sdb
...
Starting '/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_TPGS=0'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_TYPE=disk'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_VENDOR=Corsair'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_VENDOR_ENC=Corsair\x20'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_MODEL=Voyager_Mini_3.0'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_MODEL_ENC=Voyager\x20Mini\x203.0'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw'(out) 'SCSI_REVISION=000B'
Process '/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/inquiry --raw' succeeded.
Starting '/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/vpd_pg80 --raw'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/vpd_pg80 --raw'(err) 'unable to open binary file /sys/block/sdb/device/vpd_pg80: No such file or directory'
Process '/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/vpd_pg80 --raw' failed with exit code 52.
Starting '/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/vpd_pg83 --raw'
'/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/vpd_pg83 --raw'(err) 'unable to open binary file /sys/block/sdb/device/vpd_pg83: No such file or directory'
Process '/usr/bin/sg_inq --export --inhex=/sys/block/sdb/device/vpd_pg83 --raw' failed with exit code 52.
Starting 'probe-bcache -o udev /dev/sdb'
Process 'probe-bcache -o udev /dev/sdb' succeeded.
Starting '/lib/udev/vdev_id -d sdb'
Process '/lib/udev/vdev_id -d sdb' succeeded.
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb2/2-6/2-6:1.0/host2/target2:0:0/2:0:0:0/block/sdb
DEVNAME=/dev/sdb
DEVTYPE=disk
MAJOR=8
MINOR=16
ACTION=-p
SUBSYSTEM=block
SCSI_TPGS=0
SCSI_TYPE=disk
SCSI_VENDOR=Corsair
SCSI_VENDOR_ENC=Corsair\x20
SCSI_MODEL=Voyager_Mini_3.0
SCSI_MODEL_ENC=Voyager\x20Mini\x203.0
SCSI_REVISION=000B
ID_SCSI=1
ID_SCSI_INQUIRY=1
ID_VENDOR=Corsair
ID_VENDOR_ENC=Corsair\x20
ID_MODEL=Voyager_Mini_3.0
ID_MODEL_ENC=Voyager\x20Mini\x203.0
ID_REVISION=000B
ID_TYPE=disk
ID_VENDOR_ID=1b1c
ID_MODEL_ID=1a0c
ID_SERIAL=Corsair_Voyager_Mini_3.0_070851D0E490C776-0:0
ID_SERIAL_SHORT=070851D0E490C776
ID_INSTANCE=0:0
...

Installing the version: 1.44-1ubuntu1 in Disco fixes the ID_SERIAL issue (enough for now).