Today's update is version 5B59, up one from the previous version of 5B58. Unfortunately, Apple doesn't reveal exactly what's new...
Version 5B59 release notes
Bug fixes and other improvements
Firmware updates are delivered periodically while your AirPods are charging and in Bluetooth range of your iPhone, iPad, or Mac.
To use your iPhone or iPad to check that your AirPods are up to date, make sure that you have the latest version of iOS or iPadOS. Go to Settings > Bluetooth, then tap the Info button next to the name of your AirPods. Scroll down to the About section to find the firmware version.
If you don't already have AirPods, there are some minor discounts available today.
● AirPods Pro 2 - $239 ($10 off)
● AirPods 3 - $159 ($10 off)
● AirPods Max - $499.99 ($49.01 off)
Please download the iClarified app or follow iClarified on Twitter, Facebook, YouTube, and RSS for more software updates.