Blizzard if your app starts taking its own actions further I’m uninstalling you. I did not tell it to install WoW Classic, and only knew it did because it popped up saying it had finished installing. I only play WoW official. Not acceptable for this to happen.
This may be better in the Bug Report forum. I’ve have the since it rolled out and now the new live version and it hasn’t installed anything without asking.
The Launcher is set up to manange installs and even updates for games based on your settings.
Blue Swirly logo > Settings > Downloads - Under the Automatic updates section select the option preferred, including Game specific which lets the player control everything.
I mean more like what (I think) the OP is talking about. Not so much updating, but actually installing a game that wasn’t previously.