Hauser made these statements in a 2022 Vanity Fair piece that took an in-depth look at how Sheridan and "Yellowstone" co-creator John Linson went about assembling their ensemble cast. As it turns out, the series' masterminds weren't overly concerned with how the actors who played Beth and Rip got on during the casting process.
This apparently changed when they glimpsed the potent chemistry Hauser shared with Reilly during a key scene in the pilot, with Hauser claiming, "Initially there was a scene where we were having sex in her bedroom on the dresser, and she slaps me, and the way I reacted..." The actor continued, "I remember walking out of that scene and everybody was just kind of glued to the monitors ... And I looked at them and they just all looked up, like, a 'Wow, that was amazing' kind of feeling."
Per Hauser, this specific scene led Sheridan and company to flesh out Beth and Rip's relationship in ways they hadn't previously considered, as "from that point on, [Sheridan] started really penning it more and really giving us more to do and giving us more opportunity. And then also pushing us and making us take risks together." This relationship has arguably become the heart of the entire series, and given the way the "Yellowstone" fandom clearly feels about Beth and Rip, this is unlikely to change anytime soon.