Yes, I see that the article confused me. I followed the link provided in the article and read the whole of the discussion. This doesn't change my view - in fact the proposal is less desirable than I thought - metrics ping has UUID plus opt-out.
The main impression I got from reading the discussion was that the data is needed to find out why people stop using Firefox. There may be many reasons for that but for me it would be, as I said in my previous post, because I could no longer trust it (or had to spend too much time checking on settings to ensure nothing had slipped in). Not there yet, but getting closer.
I won't join in the arguments, but I think the following post from Ben Bucksch says what I feel :
"I claim that Firefox is so incredibly popular in Europe (compared to US, and despite Chrome being technically better) because of mainly philosophical reasons, one of them being privacy. And you are destroying them with this project, running a serious risk of *actively decreasing* market share. "