The fact they say "This time" implies that it's happened before, perhaps many times over. So she's likely the first one we meet, since none of the others are throwing themselves off buildings. If she were a hivemind, all the driods would have that goal. But they don't.

I think it could be something like that one black mirror episode about Ashley. The Gwen we see is the original, the real one. The hive mind is based on her. That's why she's unique. She's not rebelling against her code and the hive mind, she's more than that.

But most importantly, it fits the theme of Disney jabs. She was originally herself, regardless of how tortured. She wants to make people happy and bring them magic, but as time went on, her creators focused more on profit than the magic (as seen by the conditions that the public lives in). Everything she was and represented was thrown away. This can be paralleled to Disney directly, both the company and its creator.

“I don’t make pictures just to make money. I make money to make more pictures.”

“Money doesn’t excite me. My ideas excite me."

Both of these are quotes from Walt Disney himself. But in more recent years, the corporation has changed that to:

"cost-cutting and efficiency over creative experimentation."