And this is why you're never going to get people to use it. I get that you want to know what is being used, but really -- this is a terminal. You can't have any kind of telemetry for a terminal.

If you had a very big notice when you install, asking for permission to send which commands get autocompleted, you'd have likely been in a better position. Debian does something like this on install -- asking permission to track what packages you've installed. But it very clearly optional. And their level of knowledge is just that a package was installed, not necessarily how frequently it it used. Anything approaching telemetry within a terminal is just a bad idea.

And I fail to see how you couldn't also get the same data from surveys, features requests, issue tracking, etc... It wouldn't be the same quality, but this is really really bad. And because you started out with this major faux pas, you're going to have a major problem with trust going forward.