There's a lot that happened this issue and I loved it, but for now I'll stick to what's sure to be the main discussion that will surround this issue, which is actually the least interesting thing about this issue for me, but whatever.
The ending of this issue heavily alludes that:
spoilers:end of spoilers
New 52 Lois and New 52 Superman are Rebirth/Post-Crisis Lois and Superman.
The hooded figure that's been appearing in this book turns out to be Rebirth Lois Lane, and when Lana is "dying" just like Lois did, Rebirth Lois tells Steel that the same thing that happened to the other Lois is happening to Lana, "the same thing that happened-- to me".
She even calls Lana "Red", like New 52 Lois did.