Well perhaps a bunch of dialogue wasn't added, but bugs that was causing the dialogue to be skipped was cleaned up? Alpha for me was basically only sex scenes, which is why I was fairly disappointed with the alpha release. But playing through the Beta I got a bunch of dialogue between Ian and Lena, Stan made some appearances outside of yelling about Jeremy, Holly reflected more on her relationship with Ian, Ivy called a loving Lena a prude when talking about the Holly Hole scene which I didn't get the first time.
Also, and this is less likely to be noticed. But Ian's opening thoughts at the start of the game when before he gets chewed out by Minerva has been altered. There were also some changes to dialogue between Lena and Seymour from the previous update. And, as usual I'm sure several other small changes to conversations and thoughts have been changed throughout several chapters.
This entire scene from the opening is new to me, I didn't have it during my 13.1 playthrough.
View attachment 4433587
Edit: Actually, holy cow! So much of chapter 1 has been changed. Cindy arrives after Ian to the apartment now, and has a much more engaged conversation with Ian. Perry immediately comes across as more prissy and entitled. There is an entire scene of Ian walking home from his internship with his thoughts.