I always played like that after meeting Bella. And the whole Episode 8 was about making a decision who to go for. So I do not think that the Interlude did this as well. The whole game is about growing up how your wild life will change after meeting the right person etc. For some it is to move on like with Bella and her marriage.After the end of season 2, DPC wrote that he wanted to present the next story in a completely new light. If his new vision looks like an Interlude, then probably many will be upset. In the Interlude, there was more emphasis on relationships than on obscene content. On the other hand, the emphasis on relationships will destroy that unique atmosphere of student life and make the story more serious.
Zoey does not change anything IMO. She jsut comes in to get more drama that is not really needed. I love this game and personally it was my GOTY overall sicne it was such a huge surprise for me and an introduction of this "industry" but this was pretty weak for me.