You know, what might seem fake to one person or system might be exactly the opposite for another. That can even be true of the different members within one system.

In my system we had a handful of alters that were always very adamant about who they were, and absolutely did not like being mistaken for one of the others. Those few often would be quite vocal about making themselves known as themselves. But for the other 90%... they were shifty and hidden, and never announced their presence to anyone. If they were ever recognized by someone outer, such as T, they quickly withdrew or disappeared. Most of our system was very hidden. That was how we needed to be for our protection in our particular circumstances.

Naming oneself and standing up for one's identity can be for any number of reasons that are very specific to each individual system. It may seem 'fake' to a different system who evolved to meet different needs in a different set of circumstances. I guess it's even 'okay' for that to feel fake to another person or system... maybe it doesn't resonate with you because your system is different. That makes sense, and it isn't 'wrong'. It's just a point of difference.

In a different system naming oneself might meet a very real need. It might even be absolutely necessary.
During the course of therapy one of our alters was extremely vocal about being herself and not one of the others. She needed to separate herself from everything else because she wasn't ready to accept it - it hurt her too much. So there was a period of time when she always announced herself and made sure everyone around her knew that she was NOT associated with the others. She always put her name on anything she wrote, because that was her very real need. She always wanted to be known for her and did not want to be mistaken as 'anything to do with those others'.
It wasn't at all fake. It was just what she needed to do for her (and thus for all of us).

So if some alters in other systems name themselves in posts, or don't name themselves, or anything at all really, I guess maybe that is just what they need to do for them. It is what works for them. Even if it is really different to what we need to do in our circumstances.