Watch the ending credits, there are over 20 people who are just playtesters.
Do realize (every time this is brought up) that an English-Language test server would only be for testing localization changes, not gameplay changes. The developers would never want to create a situation of duplicated effort where they have to localize changes THEN test if they work.
With the games that have test servers, they often have the following limitations:
1) The server is closed at all times until something needs to be tested
2) Only the new content is available (sometimes the GM has to set a bunch of things on your test characters to start at that content)
3) For non-native language (that means English for a Japanese game) tests are only concerned with localization, not gameplay, except where the gameplay was explicitly made easier for Western tastes.
4) Feedback on features not requested testing never makes it back to the developers, only the feedback on the features requested testing. So again, Japanese game, only Japanese playtesters test the mechanics. English playtesters only test the tooltips, NPC's and cutscenes. It's also been stated that localization goes in both directions due to how the lore is setup.
5) You will not be allowed to talk about the testing process, screenshots, video, and even letting your friends know about it likely means you are never allowed to test anything again*.
We all saw an example of SE's testing process from video from MrHappy and MTQ 's media tour, and quite honestly I hope SE doesn't allow Western Media to do this again, because it riled up people based on subject-to-change details because the OPINION of the people they allowed in the media tour.
Next time, if there is a next time, SE should not bring youtuber "channels"'s to the Media tour. Bring people who are capable of producing video for Youtube, but have neutral opinions on what the game should be.
* Westerners have a bad habit of bragging, thus people who are in guilds/FC should never be permitted to test, otherwise they will always leak that content to their guildies to give them an advantage. In one game that I was a tester for, it was a never-ending revolving door trying to find testers that wouldn't leak information, and it even resulted in some features being dropped and never released due to the leaks. That's all you need is one of your testers to be a data miner, and having to push back or cancel content because that one tester leaked something that wasn't due out for the next few patch cycles.