Some metacontext for those who don't know: Curse was the de facto WoW addon manager. Then Twitch acquired Curse and absorbed the addon manager functionality into their client.

Now Twitch sold off the Curse/addon functionality to a party with a much less-polished addon system.

Thus, there is now a new market for addon managers, since there is a new major expansion coming out, and playing modern WoW without mods is not great.