That kind of makes sense? Aren't the labs when they're A/B testing or benchmarking new features before general release and toggle random people's settings doing so? I vaguely recall some drama around that.
If I turn off telemetry I want those off too, it makes sense they're linked. It you want a new feature there's always nightly+about:config, but I don't want it downloading random config toggles especially if it's not reporting back that it broke my stuff. The code should be what I installed and compiled by my distro, not some random lab blob downloaded off their servers at runtime.