their "big update" might have been the replay-functionality. Remember that these people did that as a hobby, for them it might have been a big thing.
perhaps the "big update" was that they actually got a meeting. no one expected them to get invited to blizz HQ.
And yeah you might think bad of their self-proclamation as ambassadors, but they kind of ended up kind of being them.
I don't know what exactly their opinion is or if they behave properly - we know next to nothing about them.
BUT they actually got to meet blizz about legacy servers, unlike you and me.
I would prefer to look at it with a more positive view - they at least appear to have taken their opportunity serious, at least tried to.
who knows what was talked this weekend, but the description of ambassador is not that far-fetched even if it is lousy to be self-proclaimed.