I think that's just fallout from a lot of people complaining that Lena was being hypocritical for getting angry at Ian for cheating on her, and then having the option to cheat on Ian. Rather than rewriting things, Eva Kiss decided the easiest way to sidestep that criticism is to simply make it so that Lena CANNOT cheat on Ian with Holly.
Nah. The hypocrisy itself isn't even what bugged some of us. It was justifying Lena's strong reaction (and potential hypocrisy) to Ian/Holly in the writing somehow, which was completely missed/skipped over and felt glaring to us that have come to expect consistent quality from the main paths. Eva just changed this part as well because, as a few did criticize, Lena's reaction to Ian/Holly was strongly based on her care for and protectiveness of Holly. With that kind of motivation, it wouldn't make sense for Lena to put Holly in such an awkward position if she truly did care for her, as Lena had already proven her protectiveness and care. I think that hypocritical turn could've worked if justified in the writing as well, just by changing or adding some text in a few paths, but Eva chose to just take this path of locking Lena/Holly out instead in this situation.
Not a change most of us were expecting. But I think it was a way of avoiding more complicated plot situations that she would have to write content for. Could it have been done more smoothly? Yes. Definitely. Was hoping that smoothing out would've happened in the final, but it's probably a little bump we'll have to live with unless there's a post-final re-do.