As a routine user of IRC: This scares – nay, terrifies – me. London Trust Media is colossal. They seem to have control over freenode and Snoonet, two networks basically unchallenged in their niche. Snoonet hasn't been doing so well since Discord, but that's another story. They also seem to own Private Internet Access. If a player becomes too big, they'll change the rules of the game. Just look at the state of Interne…
It doesn't preclude from the issues of slack being solved by another group.
edit: For the IRC uninitiated who enjoy drive-by downvoting: Slack is IRC-inspired - the concept of channels, usernames, private messaging and bots.... in slack is almost all directly inherited from IRC.