Apple has today released iOS 12.3.2 to address issues with portrait mode.
According to Apple's release notes via 9to5Mac, “iOS 12.3.2 resolves an issue that could cause Camera to capture Portrait mode photos without depth effect on some iPhone 8 Plus devices.”
At the time of writing it is believed that this update may only be available on the iPhone 8 Plus.
As iOS 12.3.2 did not have a public beta, we are unable to confirm at this time whether there are any changes for blind and low vision users. However, as it appears to have been released to address a specific and critical issue, we do not anticipate that there will be any significant changes beyond the one mentioned above. If you do encounter any enhancements, fixes, or regressions during your own use of iOS 12.3.2, please let us know by posting a comment below.
iOS 12.3.2 is available via Over-the-Air Update (Settings > General > Software Update) or via iTunes on a Mac or PC.
Before updating, we strongly recommend making a full and complete backup of your device (either in iTunes or iCloud, depending on personal preference). This will ensure that, in the unlikely event that something goes wrong during the update process, you will have a current backup on hand in case a device restore becomes necessary. Also, if using OTA update, we recommend plugging your device into a power source for the duration of the download/installation process, so as to prevent the unlikely event of your battery going dead during the update.
More information on how to update the software on your iOS device is available on this Apple Support page.