It is still possible to get OTA Updates for the Xperia Z2 Tablet (Snapdragon 800) using the AICP Rom too. I'm really glad that I bought this device..
Link: https://forum.xda-developers.com/t/rom-official-aicp-15-0-q1...
...for as long as the maintainer continues to support the device. And maintainers are all volunteers.