What will happen to all the progress after beta is over?

I’m a player who sadly isn’t part of the server currently, but am waiting for the beta to be over, but wanna know, will all the stats and cosmetics be reset when the server goes out of beta? All of it isn’t necessary, but I wouldn’t wanna join at a point where I have no chance to climb leaderboard or be the first to get a cosmetic.

Also, will there be like a special cosmetic or item to all the beta testers?