Yup, it's 1st gen to 2nd gen - they clearly say "it was changed to accomodate the new switch form factor".
Two things: first, even though there are some reports of Apple Store people claiming that Apple started reinforcing or changing the switches, I don't really think that's true, to be honest. Second - I don't think issues are widespread. Please, if you have keyboard issues, I really feel for you and you have every right to be dissatisfied, but I have to say that, other than hearsay, we still have no evidence that this keyboard is failing at a substantial rate. There is a lot of people without any issues out there. I know this may piss off some users here, and again, I understand them, but I don't think people should really be scared to go out and buy a 2017 MBP. Most likely they will get a great keyboard, and a very small percentage may have issues - and will end up here to talk about it.
Just my opinion, please don't get pissed if you disagree.
Based on checkins, the keyboard seems to have more frequent issues than the older style, but the quantity of these issues are relatively small compared to the total number of MacBook Pros being sold.
There is not much we can say about the longevity of the new design because it simply hasn't been out long enough. However, I would not let that discourage someone from enjoying the new design. There is always AppleCare for some extra coverage anyway.
On your first point, I believe the keyboard was in fact slightly modified, but I will have to ask one of the techs to take a peek at a display model.