Hi again, the Fallout New Vegas game extension comes bundled with Vortex, you cannot remove it; you've received the other game extension updates as part of our emergency game extension fix deployment functionality for bundled extensions. The only reason why you still have those entries (FO4, Witcher3, Halo) in 1.13.1 is because you disabled the game extensions, which tells Vortex not to check if the updates are superseded.
I think you misunderstand how Vortex works - it does not matter which games you have installed; Vortex offers modding support for around 400 games at this point; and the intricacies of how they work together require us to sometimes push updates and/or extension requirements to all users, not just a select few. The game extensions you receive updates for will usually be under 200KB so it will incur minimal disk space.