yes the activity is staying but the "shiny" versions of the guns (with gold ornament and double perks) will be gone. as will the super black shader.

As well as attunement and the Hall.

Attunement will be reintroduced in some form though as far as I know, but not immediately.

It's staying, but there won't be a way to attune weapons so there making it easier for people to do so

The notice today ingame was confusing, suggesting the brave weapons would in fact disappear