I'm not sure how much can be read into the performances of the 'big names' in that last round. I suspect finding a way of getting through rather than blasting their way through was the order of the day.
These teams would know that, like all the bigger tournaments in sport, the longer it goes on the more likely it is that the bigger teams will go through so extra time is, if anything, to their advantage. Not many of them were busting a gut in the last 10 minutes of regulation time. They were relying on counter attacks while staying defending from the midfield back.
Now that the eight group winners will contest the quarters (what was that accy worth before the last round started?) it will be interesting to see if they open up a bit. Neither side will be particularly advantaged by extra time unless they are pretty sure about the content of their cojones in a [penalty] shootout.