is that it shines a huge light on the risk to users and intermediaries of having any telemetry at all in their infrastructure. The only reason they can conceivably enforce this for older Unity versions is if the software distributions are already phoning home every time they run an install process. Presumably, when a Unity game was made five years ago, no one (including Unity!) expected the telemetry to be used to extort devs down the line. But times changed and heels turned and now it is.
Which makes this a pretty dire case study for anyone else who's looking at infrastructure that has, or wants to add, some kind of telemetry. Sure you say it's just for collecting error reports now, but what happens five years later when your company gets bought by a hedge fund that starts sending out bills per user install?
very much this. It's one thing for an open source project, like KDE, to include telemetry to prioritize improvements, and even debatably different for game devs to put telemetry in their games that they own for such ends.
But a for profit middleware company offering no opt-out: this was always going to be used to strong arm developers, it was only a matter of time.