The only potential problem I see with this is high powered servers beating up on lowly servers in the first few weeks.
Actually, another problem would be certain servers throwing their matches in that week so they get put into lower tiers.
Now, I'm not pointing any fingers, but I'm sure we all remember what happens when a bunch of people go to a low tier server and end up inflating its population to the point where they have double the players that the other two servers have combined.
The only reason I can think of that these people would do that would be because they like to PvD and they like to win against people who have zero chance.
So, sadly, even if as little as a few guilds on the more evenly matched servers decide to take the week off, it'll result in them getting knocked down to an 'easier' tier.