Did they buy $100m worth of Bitcoin just for hold or they simply plan to attract more attention to their company? If they are Asian game company, and everybody knows how players from Asia like grind-like-games, I think it was not just a purchase. They will produce an NFT base games or something of that kind.
Probably, so there's a lot of window for them for purchasing bitcoin. So it's a good decision as it could be a win win situation. If bitcoin goes up, so is their reserve assets, if bitcoiners found out about their investments, maybe they are also going to invest on their company. And then we have the world of NFT which they can take advantage as well.
So it's a well thought process by the company, specially that they mentioned that they are in for the long run. So they might have set the precedence in Japan and other tech companies might follow their footsteps.