Eh.. sometimes he has an idea and puts it in with an intent to come back to it later some day. Sometimes he changes his mind and just hasn't removed it from the code. In this case, the intention was to eventually have Ann and Chris on all routes.
I think
SnowyS is on to something here, though. There´s entirely fleshed out dialogues over multiple chapters/updates, up to version 8.3 (I couldn´t check current version as I don´t know where the scripts are in the original, only your port.)
Besides the alternate dialogues there´s also several scene variations and actions. For example if Chris hates you but has Ann´s number he would pretend to not get an extra ticket and go to the Movie with Ann alone by default. Or he snitches on you by messaging Ann and telling her to come to the bar, when you are there with Jenny.
Entirely possible this was all locked consciously, to be added retroactively, or not at all, but on the surface it just looks like a missing entry point. Especially since this appears to be continuously worked on, over several chapters up until very recently.
Since you got an in with the Dev, it´s probably something worth asking him about.
Somewhat urelated, while looking at above I also found a minor error in a dialogue during the first Jenny date. If you did not go to the Movie with Ann, you and Jenny still talk like you did, regardless. It´s not a variable error, just wrong text. (it´s in TTricks version and your´s, by extension.)
I guess we´ll have to wait and see.
