I realize this is common practice in walled gardens and just to get a link preview. However the amount of data gathered about me as (through slack) authenticated user (with a paid subscription) is staggering. I think in case of Slack (compared to facebook and linkedin) it's specially intrusive because people get asked to join slack to collaborate in organisational settings. They don't have much of a choice unless they subscribe to the privacy policy of the tools their employers chose. In this setting you won't register as an anon pseudonyme but your real name. When I sent a link in a private direct message on slack that has never been sent out to the internet 3 mins later I got a slackbot visiting. My conclusion is: The data they create has massive value and must be part of the reason why they're swimming in VC money. As a user this is disappointing because I'm the product (even I'm paying). SaaS and Cloud businesses are becoming a pest to society IMO.
It does that to show a preview of the content of the URL next to the link in chat, right?
How did you think they display those inline previews?
It's no different to a random crawler. What's the actual problem? Is it configured with your internet banking credentials?