I’ll put in my two cents without the advantage of reading all the posts in this thread.
I think that a girl talking yeshivish is a shtick. I doubt that there is much toichen behind it. I doubt that most boys have toichen behind it. I see it as harmless, but some boys will like it and some won’t. In the end, you have to find someone who you can relate to. If the shticky talk breaks down some barriers to communication, then it’s a good thing. On dates, both sides want to impress. Such talk is the girl’s way of showing that she can relate to what is chashuv to the boy. Keep in mind that this kind of talk will probably end either right after the wedding or as soon as the reality of life hits both of you like a ton of bricks. So enjoy it for as long as it lasts.
If, by chance, there is toichen behind the girl’s talk, that’s another story. A special boy, who is confident in himself, will see it as an advantage. Others may get scared off.