At the moment, when a user joins a group, they can see all of the history of the chats/discussion/etc in that group. This is a potential security weakness, as it allows bad-actors (infiltrators, corporate trolls, etc.) to view the entire history of a group – potentially years of trusting relationship-based collaboration, that could include statements that become damaging or even incriminating when taken out of context.

Additionally, with AI, it's easy to process huge amounts of such data, asking questions like "who are the main power holders in this group, what are their weaknesses, and how could this group be disrupted."

Although it might be easy to discount such issues, it's worth considering that infiltrators have intentionally disrupted groups doing work as innocent as campaigning for safer roads and more cycle lanes. It's not far-fetched to imagine seed monopolies doing all they can to disrupt seed-saving groups, and a host of other issues like this.

With end-to-end encryption becoming the norm, people are now used to new group members not being able to see previous chat history.