They do have "Worldshifts", or something of that order, whenever a server gets overpopulated. Mainly, they offer you a one-time-only chance to move to another server. So if they open up new servers, most likely all other servers will be offering their players to travel to the new servers, as to have a more spreaded out leveling range.
Otherwise, how long would it take to start having HQ synths available at the new AHs? And for how much would the new items will be selling?
In any case, considering the Europe market will be mostly online during a free timeframe, the impact of their inclusion should be minimal during their non-peak hours. And the new areas will serve as buffers for that small left-over impact most likely.