If you’re unfamiliar with KRACK and would like to read up on it, you can head here and here. The major takeaway is that it affects almost all WiFi connected devices because it’s a vulnerability with a WiFi protocol, not necessarily an OS or platform like Android. It affects computers, smartphones, tablets, etc.
Also listed in the changelog for these tablets are connectivity fixes for Zagg Bluetooth keyboards, plus system stability and security optimizations.
If you’re still rocking a SHIELD Tablet, go grab that update.