I don't think the unlockable Shinnok/Mileena/Shang leak was completely bogus. I'm pretty sure the leaker who leaked that also leaked cetrion's bio which turned out to be true. It's very possible NRS changed up their plans due to leaks and/or had to cut some characters...
I'm 70% sure that the original "leak" was correct, but whoever decided to share it just took that leak and added a few names based on available info (like there is 100% a Shinnok model in the game, Shang Tsung was being worked on, Kitana's moveset has many Mileena moves, etc.). But we'll see.
That said, Mileena fans are starting to freak me out. I don't remember nearly this much hubbub over her when she skipped vanilla MK4, Deadly Alliance, or MKvsDC.
I wonder if we are. Seems like the game in coming in hotter than previous years. They clearly are behind in their production schedule. It probably wasn't ready to show at e3, they've shown us a bunch of stuff that has changed late (d'vorah being the most noticeable), and the gameplay balance and variations don't seem to be as on solid footing as when MKX came out. The fact that they are only launching with 2 variations per character and that they didn't really start showing the real variations until a couple of kombat kasts ago is also telling.
I keep hearing this and none of this seems accurate, largely because they've been releasing tons of info at a breakneck pace. Lest we forget, we didn't even know the game was being MADE until just over 4 months ago. Going from announcement to reveals to release has been a breakneck pace, and I don't think they're "behind" on anything.
If anything, everything they've shown has been at a much faster rate than I'm used to them revealing and even finessing. It's repeating what I saw them doing with MK9 and MKX, and those turned out just fine.
That doesn't mean they won't tweak stuff based on feedback. Lest we forget, MK9 and MKX had exhaustive revisions post-launch.