Just do once and see how long it takes for the players to find out that there is a new job in the game. You do it while the game still hot. Then watch the message boards blow up and user base teach people were to get it. Then like a month later tell the people were to get the job quest.
It not like right at the moment they need to amp up there users base , by showing the new jobs right now.
The thing is, they can't just 'drop it in' - that kind of addition usually requires preparation in the form of code/dat files for the Job/Class to be added into the game via patches prior to it being 'activated' - and as the community is notorious for dat-mining, someone would be bound to discover it and would be very quick to let that particular cat out of the bag.
So yeah, it just wouldn't be possible for SE to 'slip in' a new Job or class into the game without the player community realizing it.
It could be if you insert dummy data. For instance by adding data of class/job prototype, then with multiple "futur" data there would be more difficulties to find actual new content. However it only work if there is no explicite way to tell if content if activated (accessibilty to quest) and would require too much effort to provide real content (like quest text) for fake/prototype.
But I'd like that to happen.
I feel like not hyping up an addition such as a new job would be a missed opportunity.
People would data mine it anyways.
Players would find it in the data before the game even went live with that patch. We can always download the patch while the servers are in maintenance so we'd know before we even had a chance to play.
even with data mining, the majority of people would be surprised if they just threw one in there. I think it would very funny to see the community reaction if we logged in tomorrow morning and suddenly there was a somewhat obscure class added like Oracle, Sage, or Berserker
This would be awesome for so many reasons but it's probably not going to happen. If there's anything that time has killed with Videogames, its the genuine surprise of content. A new class is something Square would most definitely want to make public knowledge as soon as it was solid info.
But even with Datamining, the vast majority of players would likely be blindsided by it.
Addition of new Job is a good morale boost to get people playing.
Also interest new players.
Not using this opportunity is bad business. :P
But i hear what you are saying, the thrill i guess...
It reminds me of this story about Valve special announcement for Portal 2.
They did put some new Easter eggs on Portal 1 and some people noticed it, talked about it on forums and those secrets were some clues for something. People did some impressive detective works and it turned out it was Portal 2.
http://half-life.wikia.com/wiki/Portal_ARG
They could put a job without announcing it directly and let players build up the hype.
The first MMO company to completely ninja-patch in jobs or extensive content into a game with no patch notes would be my hero company.
I mean, imagine if 2.2 was added and the entire FF community (minus dataminers) was blindsided by it. You'd have 3 new dungeons, new story quests, 2 new primal fights and more coil areas to not only play but explore on your own.
So instead of patch 2.2 being a checklist of content to play, it'd be like....well a traditional RPG where you just keep playing and enjoy yourself.
The only issue with that is that it would create a terrible inconsistency in the mind of the player when they run out of content.