PvE should be released shortly behind the fresh realm.
What server comes first?
We have thought long and hard about this decision. The staff is in unanimous agreement that the Nostalrius PvP realm will come first. We understand that the majority of players are looking forward to playing on the Elysium PvP fresh realm. However, there are significant reasons to launch the Nostalrius PvP realm before the fresh realm. The Nostalrius PvP server is the most significant aspect of this revival. A huge part of our success will be in the result of being able to bring your characters back. This will only add to the reputation and hype of the project, lending more respect and population. Population is also a large aspect of our choice. Releasing the Nostalrius PvP realm first will minorly effect the population of the fresh realm. However, based on polls, the Elysium fresh realm will have the most active players, and so by launching in this order, we effectively balance out the two servers. One last reason is bug fixes. By fixing bugs before launching the brand new server, we will be making it a far more pristine place early on, and in the future. However, do not fear! There will only be a 3-4 week period between Nostalrius PvP and the fresh realm.
Also, one paragraph covers the upcoming stress test:
We would also like to inform you that the stress tests will not be branded to specific servers. This is a general test. We will begin with the old Elysium hardware in order to gauge its potential with the optimized Nostalrius core. We expect this server to cap out at around 5k players, and if it meets our expectations will use it for the smallest of the three realms.
We all know which server that's going to be...
Everyone who actively played one or more characters on the PvE server knows that a pretty big chunk of the playerbase was playing on this server not because they really desired a PvE server, but because they either wanted a fresh start or found Nostalrius only recently and saw it as an alternative place to stay to prevent having to play on a server where they would be many months behind in comparison to the vast amount of players that had been playing for many months on the PvP server. Releasing the PvE server last leaves the subset of the already small playerbase that really doesn't want to play on a PvP server.