If you’re on the EU server, you can now buy Scharnhorst! I don’t know why exactly there was a delay between EU and NA – or why NA got it first to begin with – but that’s in the past now.
You can buy her bundled or on her own, and the biggest bundle also includes this fancy commemorative flag:
She’s a very fun ship, but also very punishing if you don’t play her properly. Scharnhorst isn’t really a battleship like the regular ones in game; treat her more like a cruiser and go after enemy cruisers. She can tank quite a lot of damage if you angle her right, though, so don’t forget about your armour.