Hi Myke, I hope you're doing well!
I'm sorry for the inconvenience this may cause, but currently, there are no plans to update all of the K22 Family of MCUs to newer versions of the MCUXpresso SDK.
The latest version available for the MK22FN1M0Axxx12 is currently 2.3.1, as the version is considered a part of the "Legacy" versions, using the TWR-K21 development platform instead of the FRDM-K22F
This document here explains the differences between the different versions and changes to the K22 MCU family.
Please let me know if you need any more information.
If I read the table in the link you sent, there are no "K2" devices with more than 512k Flash and 100 IO pins. Everything else is "Legacy"?
When I hear the term "legacy" as applied to any chip it says to me that support has ended. Along with that, the referenced post is dated four and a half years ago, which tells me NXP has no plans for providing an MK22 "K2" version of the device with 1M Flash and 144 pins.
Could you please tell me how long you expect the MK22FN1M0AVMD12 to be in production? I've just gone through the exercise of porting from the MK20DN512VLL10 and I want to know if this work was in vain.