This idea has been rumbling for years. Koppleman however, does not appear to have ever embarked on writing a follow up.
A Rounders Two would be interesting - I believe I posed a story outline some time ago here about how the characters might have progressed. Matt Damon's character could have aged into a Billy Baldwin type (superior player who became a casino executive ending at MGM Resorts) and Edwin Norton could have graduated from small time con man to sophisticated scammer taking
casinos for big money...and the two would ultimately clash once more, this time in Las Vegas.
The problem being I think it would have to be somewhat of a more sophisticated story to be able to raise funding. That is where I believe Brian Koppelman knows his lane. Rounders cost $12 million and grossed $22 - it made money, but I am not convinced it would broaden its appeal. Poker players love it because, well its a film about poker. However I have noted before, if you watch Rounders a few times (more importantly recently), it does not really hold up and feels dated. If it was regarded as a classic movie it would be featured and promoted quite heavily by streaming services and though it is available it is not widely so . A streaming history now provides an incentive or not for a filmmaker to consider whether a sequel might be viable.
Another thing to bear in mind is I am sure Brian Koppelman paid close attention to films such as The Card Counter last year. Brilliant director, Paul Schrader, brilliant lead in Oscar Isaac and very good reviews but the film tanked at the box office when it took $5 million only. Poker Face with Russell Crowe will also be released in the near future (it faced production delays) and though I expect it to take more that The Card Counter, I am guessing that won't be a big hit either (plot sounds contrived).
All that said, I think the route to take would be to try to get a streaming service to fund a drama series around poker. Attempt to keep the costs down going in and maintain a flexibility about how the story arc might develop.
