So that we don't "count" that ping as a unique user. Our goal is to get a rough gauge of how many people are using Armory, and what the OS & version distribution is. That's all we use the data for. If we send a ping without the ID, we don't know if it's a duplicate.
Also, I shouldn't have suggested "just" hard-forks... a piece of secure software used by people with massive amounts of money has many different reasons users might need to be notified, including critical security issues with Armory, if they arise.
I still don't know why you need to know their installation ID for each ping. Can you come up with a real-life example of a situation where you'd need to know that information when providing announcements? if there were critical issues in Armory that would affect everyone running that version and not specific installations.
For most users privacy is just as important as security.
Annoucements/statistics should be two completely seperate things. I think statistics should happen on first-run ONLY and it should be very obvious it's happening and easy for the user to opt-out. Checking for annoucements should send the bare amount of information you require, the Armory version and platform.
I was under the impression checks for announcements weren't automatic and it seems others were too. Maybe it should be more obvious that they are automatic and easier to disable them (in the GUI) for people who want to check manually instead.