Yes and the obvious point would simply be: If Eva was supposed to be part of the harem...why isn't she already? She was introduced very early, so if she was supposed to become a part of the harem, it would've been possible to integrate her all the way back in like 0.1 or 0.2.
I might actually object to the bit about Annie though. It very much seems like she thinks that Orion and her are in somewhat of an early stage of a committed relationship at this point and I would suggest that she has pretty good reasons to do so (considering for example the dialogue between her and Orion in the kitchen). The kiss with Luna also sends considerable signals towards her in my opinion (obviously one kiss doesn't make a relationship, but still).
That actually brings up a new aspect: At what point does Orion need to tell the girls what is going on between him and...well...all of them? I don't think that point can be pushed much farther than 0.7 or 0.8 without Orion starting to look like an asshole for leading all the girls on.
Yes, it's getting complicated now. But Annie still frames what they are doing as "practice" – I know, she's shy, but she also knows how much Orion cares for her as more than a friend, and for how long he has cared, and if she wants
him to treat what they're doing as a committed relationship, she'd be up for the challenge of saying so. She's being more direct about what she wants, sexually if not emotionally. Her assertiveness when she was trying to show the others what she can do with her magic also shows she's not as timid as she used to be. And those two things she said, to me, are her saying that she'd be okay with sharing him – perhaps more than okay, given that her comment about Dalia did not even include him. I think she has a crush on Dalia.
Luna is trickier. She's more vulnerable than Annie, because until now the possibility of a physical relationship, and therefore probably any romantic relationship, has not been available for her due to her psychic ability. Of all of them, she's the one most likely to be hurt by finding out he's involved with anyone else. I think she'll accept it relatively easily (she's too sweet and loves them all too much not to) but he needs to tell her before things go much further.
As you say, beyond the next couple of updates I don't think I'll be able to defend him anymore. And he's close to being found out by Dalia or Penny, both of whom are aware the other is interested. Nova knows Penny is interested. I can't imagine it being too long before one of them figures out what he's doing. Better for him that he admits it first.