Hello,
Sorry for the inconveniences this might cause you, but that it's the latest software available for that MCU. I would recommend you to check the KW21D in case you are interested in Thread, Zig-Bee and 802.15.4 as that device has different IDEs support as well as the SDK it's been updated periodically.
If you have any other question, let me know.
Regards,
Estephania
