The question is how Trackhouse gets the third charter because both Ross Chastain and Daniel Suarez signed multi-year contracts earlier this year. The 51 is 3 points behind 33rd place in owners' points (the 77), and the charter, as the 15, was in the bottom-3 in 2021 and 2022, so if they don't improve, NASCAR should be seizing that charter at the end of the season.
Related to that, Rick Ware is probably kicking himself for swapping the 15 and 51 charters before the start of the season - the 15 is 22 points up on 33rd place, and with his son no longer racing, he could have used the money from a charter sale to help Justin Haley's chances.
The other possible sources for a charter for 2024 - the 78 (Live Fast will be on the third year of the bottom-3 clock as the team is solidly in 36th, and they're a Chevy team running ECR engines like Trackhouse), the 77 (Ty Dillon is reportedly on his way out of Spire's second ride, and Spire is a Chevy team, though aligned with Hendrick), and the 42 (GMS-Pet...er...Legacy has already jettisoned Noah Gragson, and they are a 2-car team about to move to Toyota, which hasn't supported 6 teams since -edit-Furniture Row went back to 1 team after the 2017 season).