Proper planning could have avoided the issue. Not funneling everyone into the same bottleneck 20 minutes into the expansion is MMO expansion 101. This is why most other MMOs are gating less and less and offering more and more jump points into the new content to spread everyone out as much as possible. Setting up the story so you could access multiple different paths and avoiding any instanced content until a little deeper into the leveling process would spread everything out and mitigate the lack of hardware to support a giant focused influx like this. Sure it doesn't make sense to obtain enough hardware to run clean through a huge spike, but that is a shortcoming you ought to be aware of and design around.