This last episode, without spoiling too much outside the episode thread, shows that Picard's supposed loss of authority in his demeanor has nothing to do with Patrick or his age but the writing. The strict, disciplinarian Picard came back, voice and all, this past week, just as strong if not even harsher than at the height of TNG.
Picard basically adapted a "friendly old man" persona after he left Starfleet and that's been his primary appearance throughout most of the Picard show. But it took just one episode for that strict military style personality to rush back, voice and all. It's almost like an entirely different character to be honest, on par with Batman's Two-Face even.