While the updated S-Series Eagle Drivetrains share a similar design language as Eagle Transmission 70 and 90, these two systems have some differences and components are generally not interchangeable. Eagle Drivetrain and Eagle Transmission systems use different cable pull ratios, so you must use an Eagle Drivetrain (S100, S200, or previous Eagle Drivetrain models) shifter with an Eagle Drivetrain derailleur and vice versa.
The Eagle Transmission cranksets are backwards compatible with Eagle Drivetrains when installed on Boost (148mm rear hub spacing) frames, but the opposite is not true, due to the wider tooth profile found on Eagle Drivetrain chainrings. Otherwise, you must use all Eagle Drivetrain or all Eagle Transmission components for the best performance and to preserve your warranty.