I figure so that the DPC will start from EP9 so that the rejected LI's will reveal to us girls their past dates and boyfriends and that he could create relationships for those girls.
Why? The MC, that is us players, commits us to a Li in EP8. Therefore the other girls can get boyfriends. Stupid only if the player has made several runs with different girls, because then the situation occurs, which DPC probably wanted to avoid.
I also assume so that DPC will use the karma. What the MC does to the Girl's, the MC gets back. So what Tommy said in EP8 gets a kanns new meaning. He said so it then actually gets serious after the first date. This is probably true for every LI.