That's besides the point. Why block users from using it if they want to so? If it works without any extra maintenance, great. Which, apparently, it did. Unless

That's besides the point. Why block users from using it if they want to so? If it works without any extra maintenance, great. Which, apparently, it did. Unless Slack has material amounts of support due to mobile users trying to use its web app, which I'm very skeptical about given that the app is a dumb wrapper around a web view anyway, there's no sensible reason to actively prevent those users from using it. What likely happened instead is that someone at Slack is trying to growth hack app download numbers.