Preface: I am not producing an Android app. I work for a software component business, creating shared libraries, compiled from C and C++ code, for use in third-party customers' apps. I test my libraries in a command-line test harness, which I run in the ADB shell.
I don't use the Android SDK or IDE, at all, ever. I can do everything I need with the NDK and the Platform Tools, and I'd much rather manage them myself than contend with a GUI installer with ideas of its own.
At present, I'm using NDK 21b, because validating new compilers is a long job for the libraries I provide. I've been using that for production builds since March 2020. I'm now making plans for my next upgrade of NDK, which I will start in February 2022.
Is it known what the LTS NDK will be at that date? I'm only hoping for the major version, presumably 23, 24, or 25; the letter releases clearly can't be predicted this far in advance.