I don't really rate how the new structure has shaped the pools. All six of the pools have two teams that will clearly progress and two teams that clearly will not. The only game of relevance to the tournament will be between the top two teams, and even that will just be to determine who plays who in the round of 16.
Could potentially see teams keeping their powder pretty dry until knockout stages.
I think it's worth it for the extra knockout round instead of another round of pool games, and to remove the scheduling problem of having an odd number of teams in each group (so no more games between a team on a 4-5 day turnaround and another who's had 7+)
That said in Pools B, C, E and F there is definitely potential upsets for 2nd place. Fiji lost to Portugal in the last world cup, they could lose to Spain in this one. Georgia will be extremely motivated against Italy, that could easily be an upset. A full strength and well prepared Samoa will be very hard to beat for Japan and potentially even France, and same for Tonga at full strength against the current Welsh team.
Pool A and D seem a little more straight forward, especially our pool as I can't see Chile beating us without something crazy happening. Uruguay and Portugal on a good day would have a better shot against Scotland, but either would be one of the great upsets.