"Is anyone surprised" is an important question to ask, although in this case it would be more valuable to ask on a less techy forum. I'm not surprised and many people here are not surprised, but most people are still surprised when they hear something like this, which is why they gladly give their information to anyone that asks. If the majority of Discord users knew breaches are inevitable and refused to give their information or at least took some protective measures like partial redaction and use-case watermarking, this breach would be less of an issue and/or such breaches would be less common.

We need to make sure nobody is surprised. Everyone should rewrite every "upload" button in their head to say "publish".

It's a valid question, which speaks to the frequency with which these things happen. That's isn't trivialising the problem.