I had seen that post. I don't read Japanese fluently so I have to rely on machine translations, and to me it felt a bit differently. She basically said that she doesn't necessarily sees her work as "erotic", or that's not how she intents to sell it; what she does, which is seen as gravure, is just what she likes to do to express herself, and whether or not people find it erotic, it's up to personal interpretation. She also said that she won't ramp up exposure just for more money.
About her work being erotic or not, while she has a point, if we consider that "everything is subjective", I think she was just playing coy. This position is smart because it allows her to claim that even photos with less exposure could be considered "high tier" or special if she simply likes it better than others. I never watched any of her Fantia work, but from the screenshots that people share, her own work seems to have a lot of skin exposure (maybe by "過度な露出", the "excessive exposure" part that she mentions, she means explicit work? That would effectively sound like a jab at Anju, her former Imouto colleague, for doing that kind of work now... But maybe I'm reading too deeply into it).
Ai participates in a lot of weird fetishistic stuff where, for example, she's lying immovable and then a dude feels up her entire body while she's completely covered in cream or other food condiments. She then says in that tweet that the work she does is a means of expressing herself, and not meant to be erotic, rather than doing it purely for money, which elevates her from the position of "commodity" in this kind of content to "artist", I guess. In the end, she has all the right to sell herself however she wants, and I guess she wants her fans to feel some connection beyond skin exposure. This is just my personal interpretation of it, of course.