Yeah I get it. In this case it’s being STed by the product lead. It’s like if you saw a D&D 5e game DMed by Jeremy Crawford, except that Jason Carl also has a level of charisma closer to Matt Mercer than the painfully dull Crawford. So because you’re going to the official designer, I suspect you’ll get something much closer to the official rules than a typical actual play.

That said, the reason I brought it up was actually to point to one specific thing that he does which I know is a house rule, because I’ve seen him say as much in interviews, and it suggest that this is a good house rule. I don’t remember what exactly the boundary is between the official rules and Carl’s interpretation; it’s been a while since I watched that interview (and couldn’t easily track it down when I looked yesterday), and even longer since I read the actual rulebook or watched the actual play. If you were to watch just a few episodes of the show with an eye specifically to how Jason Carl runs the Beast (and treat the rest of it as though it were entirely scripted content and ignore the actual gameplay), you’d come away with something useful and easily actionable in your own games.

As far as splatbooks, I’m not sure, but I don’t think so. LA By Night was essentially a launch title for V5 itself, commencing in November 2018 after an August release of the Core Rulebook. Camarilla and Anarch sourcebooks had also been published earlier that same month, but as far as I can tell (I own neither) the only actual mechanics in both are two and one clans respectively, and those clans were not used by the core cast.