I still consider this fairly egregious in that if you've already installed it (but not used it) before finding this out; a bunch of details has already been reported about your environment. Does opting it before install also keep you opted out of all telemetry or does that have to be done separately?

If a new starter did this on a company machine, boom, misconduct on their first day; though I hope the network/operations team have already put a block in place for that.

That is an extreme example, but it's kind of annoying you have to look this up, and make sure you didn't typo the flag for every piece of software you use/test.