To be honest I just think NRS is waiting too long to show everything off. Before the Reveal Event happened, I thought for sure that they were going to have like 10-12 characters in the playable build. Nope, just 7, roughly the same number we would get around E3 with previous NRS games. The weird thing about is that they pretty much openly showed certain characters in trailers (Cassie Cage, Kitana, Liu Kang, Kung Lao, etc) and others on menus (Kano, and who seem to be Rain and Noob Saibot), etc, so it's weird how they didn't go ahead and show some of those off in-game.
They have waited so long we are pretty much 2 months away from release and we've only seen gameplay of 8 characters. Even though most of the game is done and they are sitting on some really juicy stuff, they decide to reveal multiple characters like Kano and D'Vorah officially by using renders? Like what? Now they are getting the Achievement stuff done and are pretty much leaking everything themselves.
I'm not complaining, just saying it's an odd approach that almost seems to be backfiring in some way (mainly the Achievements thing). To be fair the rosters of past NRS games were leaked, but that's because a dev or someone close to a dev spoiled it. It seems they are putting a lot of effort into keeping things secret this time, so it's kinda a shame that they ended up leaking everything themselves anyway.
