Keep in mind that we only know about a fraction of all testers - the forum participants are a minority, possibly a very small minority. Of those, many don't post much here or on slack. Maybe they do their job and report things to WT, but the rest of us have no way of knowing any of that.
There are only 74 on slack that I know at least have what I refer to as level 3 hardware. That's the level that, as far as I know, includes are the main upgrades, but it actually covers KB9-KB11 but I don't think any real change has been made across those version that may be beyond simply changes in assembly practices or something while keeping the same actual hardware.
Of those, I only have dates for good or bad reports on 51 of them (I didn't start tracking dates until the end of June). Of those, I've only have dates since the end of August on 23 of them. Now, that doesn't mean they haven't said anything, though it often does. But it may only mean that they haven't made a specific statement that says they have no problem or that they do have one. If they had, I'd have changed the date.
Heck, of those who reported a problem that seemed worth tracking, only one has posted about it this month. That doesn't mean the others are solved though. It really is hard to nail these things down from the outside of WT. But it does seem as though the remaining reports are less likely to be happening a lot. So, to me, that is progress. But based on too limited data!
Yet I'd say even those testers are, at least most, still pleased. Just as I was in the first day of usage, while I was making a ton of mistakes even without TB issues. Because there were still advantages and also because I could see that I and the TB were getting better. Many customers won't view it that way.
I can see your point about the lack of details in their status updates. Can't object to that.