It's a different dimension perhaps. Maybe Sigmar fell through realities and has entered into a shattered realm where Chaos has not won.
I mean come on folks, they are giving you a chance to play with ALL your toys.
Isn't that what you always wanted? The chance to make the list that fits the theme in your head, regardless of force org restrictions?
Maybe now I can make that army with the Ranger-General Sylvos Tahl'Veras the Huntsman, leading his army of stalkers and dual wielding forest assassins.
I can create that army lead by Dornatha the Verdant Rage and his handmaidens of the thorn.
I can play that army and not take 3 hours so my wife txts me at 10 asking me when the [big bad swear word] I am going to be home.
I mean seriously, embrace change and give it a shot. Worst case scenario you lost a few hours of your life. Hell I do that every time I take a [big bad swear word].