The story with Squid Game goes is that writer-director, Hwang Dong-hyuk, had sat on the idea for the Netflix limited series since 2008. However, it would take him 10 years to see it go from idea to reality.
Considering how out-of-the-left-field Squid Game was, we understand why it took so long for Hwang to find someone willing to fund it and get it made. It's a risky endeavor that had zero guarantees. But, while Hwang reportedly lost teeth making the first season of Squid Game, which would have turned off most creators from pursuing future seasons, money be damned, it appears that Hwang didn't totally shut down the possibility of a follow-up season.
According to Hwang, he had planted ideas for Season 2 in the debut season, in case a new season would happen.
Hwang explained to Indie Wire that he left crumbs for future potential storylines "for myself and also the audience," adding that he is currently "in the process of structuring the story and the new games, and wanting to crystallize them into more detailed ideas."