Yes, they've said that the double is staying already. Furthermore, they said that 3.0 has been written to be compatible with current battletomes. I dont see them revising every single warscroll to include strength and toughness. As @SpiritofHokuto said, Soulblight mustve been written with 3.0 in mind, so we can likely take some cues from where they are going at design wise from that book.