That shot in the new trailer of the prince using dominate on Fabien and telling him "THE CASE IS CLOSED!" is a direct callback to LaCroix using dominate on the fledgling in 1. You can expect Fabien's gameplay to be full of stuff like this. A huge reason why Fabien was added to the game was specifically to cater (or pander if you prefer) to fans of the first game. His quests are styled more like VTMB1, the way he interacts with human characters is more like VTMB1, all that stuff.