This is a valid forward-looking concern that I think needs to be much more clearly addressed. It's one thing to have default-enabled telemetry in the toolchain itself, but once that window is open it's going to be much more difficult to close it and stem the tide of telemetry features creeping in further elsewhere in the Golang ecosystem where they'd be much more of a privacy concern.

Without a strong commitment from the Golang maintainers that this is where it would stop (have they communicated anything to that effect?), we have no reason to believe it will stop here, and all the more reason to be concerned that this is just the beginning and it will be pushed much further in the future.