The reason is that most people wouldn't care about the actual thing happening. Mozilla chooses to frame things in a way that is more likely to motivate people to action, even if that means being vague or dishonest. In this case their point #2 is dishonest because it already works that way.
In the app there is a "Share" button at the top right. After clicking you see an interstitial with a big "Post" button at the bottom. When you click that button, the chat is shared.
The ends justify the means always backfires in communication. People just lose trust in what they are being told.
There are so many examples of this. There was a poster that attempted to reduce needle reuse by showing the same needle degrading after multiple uses. The problem is that was not very dramatic (also not where the risk lies) so they increased the magnification at each stage to make the degredation seem worse than it was. People recognised this and the primary message amongst their target demographic was anti-drug campaigners lie to you.
I'm not sure how much this will damage Mozilla. Perhaps not much because they have already lost so much mana. Before coming to the comments and reading this thread, I had already thought to myself, "Can I really trust what Mozilla says anymore?".
Perhaps that makes it even worse. To have doubts that are so quickly confirmed suggests not only that you can't trust them, but you reliably can't trust them.
I want to like and support Mozilla, I'm posting this from Firefox, that makes me one of the few sticking with them. They make it so hard sometimes.
The fact that the crafting of the message and its match with the audience is poor, doesn’t mean that “Ends justify the means approaches always backfire”.
You can make a whole media empire that just spends its time saying that “The other sides is lying” and taking on the role of pointing out every crack and flaw in a wall, lavishing hours upon hours of coverage.
You can find just the right audience to support you, who themselves believe that the ends justify the means. Willing to rethink their lines in the sand for their team.
In the app there is a "Share" button at the top right. After clicking you see an interstitial with a big "Post" button at the bottom. When you click that button, the chat is shared.