Yes, it is. Commemorating the release of Prinz Eitel Friedrich, this is my take on the (inevitable) German BB split. This split is a "when" and not an "if". I just don't care when. I’ll go through the possible setups of the 2 lines first, then the stats of the ships down below.
I’m not going through AA for the ships, if anything, I would just compare the AA of the ships to the ships that already in the game. Also protection stats for the ships can be changed/adjusted by WG so I would only mention some details. I put everything in spoilers to avoid unnecessary mouse-scrolling. Just click the ones you want to see. 
And some other sources include someone I know who is a WW1/2 ship nut.
  A bit of a disclaimer: the estimated HP, based on the ships’ standard/full displacement, for the ships aren’t 100% accurate (but I did some tests and the results are very close). WarGaming may use different sources for the ships’ displacements. It’s a formula(s) I stole from someone I know and I do not have the permission to give them to anyone else.   Setup 1: Old line – All-new line
Setup 2:   THE SHIPS VON DER TANN Tier 3 - Light line   MOLTKE Tier 4 - Light line   SEYDLITZ Tier 4 Premium   DERFFLINGER Tier 5 - Light line   MACKENSEN Tier 6 - Light line   ERSATZ YORCK Tier 6 Premium or Tier 7 Tech tree/Premium - Heavy line
    O-CLASS ENTER THE GAME AS TIER IX "CRUISER" (URGH) SIEGFRIED Tier 7 Premium   GROßERKREUZER 4541 Tier 7 Tech tree/Premium - Heavy line If having 420 mm guns somehow breaks the line, GK4541 can be substituted with Ersatz Yorck with the better reload, and GK4541 can be a premium instead.   HYPOTHETICAL DESIGN FOR TIER 8 Tier 8 - Light line   H40A Tier 8/9 Premium   H40B Tier 9 - Heavy line   FREE XP VERSION OF FdG Tier 9 Premium/Freemium   H41 Tier 10 - Light line