BrokenPhoenix
Hunter
Sales of the first series of Kaiji must have warranted the costs of getting the second series released, whereas I suspect sales of the first series of Kakegurui must not have been good enough.
Not the first time it's happened for AL, nor MVM. Best to import the second series if you still want it.
Kaiji sales were probably helped by the popularity of Squid Game on Netflix. Additionally, Kaiji (along with Liar Game) has been noted publicly as the inspiration for Squid Game.
Not only that, but Kaiji is the superior "gambling" anime compared to Kakegurui, in my opinion. The gambling anime sub-genre is already quite a niche proposition, and the 'gambling' in Kakegurui isn't very good; as there seems to be very little consequence or cost for losing the gamble (aside from a bit of school bullying).
Kaiji has higher stakes and more on the line. It's a bloke trying to pay off his mounting debts or he'll lose his fingers and live the rest of his life doing hard labour versus rich school kids gambling with daddy's money. I think it's fairly clear which would be the more interesting watch and have a wider appeal.
Squid Game was popular and interesting for the same reason - participants in the games all had financial issues and the cost of losing the game was death.