SMITE 2 has one closed alpha weekends once a month since May but now the official client will be launching and going into a 24/7 closed alpha. The 24/7 closed alpha launches today and will include a number of updates including Jing Wei and a brand new god Mordred.
There are a lot of other updates as well including a new pass on the art of the conquest map along with new objectives to the conquest map as well.
The closed alpha also includes the new ascension pass system which is the new mastery system. Each god in the game has their own battle pass now with rewards to unlock for simply playing that character including diamonds (the in game currency), skins and other cosmetics.
As of now you can only get access to the alpha by buying one of the founders editions. No word on when an open beta or full launch of the game will happen but it scheduled to be released in 2025.