To be honest, I don't know those adb commands, but I think I figured out what might work. But first, since we're on this discussion forum I think I should write a couple things first...
The GrapheneOS team always dissuades people from making changes to the system using adb. If you make changes and something breaks later, nobody here will know what changes you made and won't be able to help you. Also, using adb or developer tools on personal "production" devices is discouraged since it opens up a massive attack surface.
Also, I don't know if these changes will work for you. I haven't tested them on my own phone because, honestly, I'd rather not. I'd suggest you look in to what I suggest before you do it. I have linked some stuff that should help with that.
Anyway if you're dead set on attempting to disable those indicators using adb, I'll share what I found...
Based on this commit, this list of device manager properties, and the adb commands you listed, maybe these will help:
adb shell cmd device_config put privacy location_indicators_small_enabled false default
adb shell cmd device_config put privacy location_indicators_show_system false default
And there's a last per-user setting that you'd want to change. First get the user's user ID from
pm list users (I'm using user 2 in the example below). If you're only using the owner profile, just skip this part and don't add the
--user # part in the command below.
adb shell cmd settings put --user 2 secure LOCATION_SHOW_SYSTEM_OPS 0
Other than those three changes, I'm unaware of any other things that GrapheneOS changed from AOSP that affect this location indicator, so hopefully that works.