So I just checked. On the device that I used to test my script to update from the broken 20190911, I can run my script to update to 20190912, then shortly after rebooting into 20190912, I get an update notification for 20190913. I reboot to allow the new update to take place and it has no issue updating to 20190913.
edit: one thing to note about my script, is that it was only meant to update from the 20190911 build, so it leaves out several parts of the update process that just where just not needed between those two releases. If you modify it to update to other builds that may require these extra parts of the update process you may cause yourself problems.