The historical file should include members that were actively enrolled on 1/1/2023 (even if their enrollment start date is prior to 1/1/2023) and any newly enrolled members through 2023 up to the point when you will submit that historical file.
Incremental files can contain only enrollment changes since the last submission (new enrollments, enrollment end, product change) or it can be a submission of all active enrollment for that month, as long as the file reflects enrollment end dates – either disenrollment or disenrollment from one product and new enrollment in a different product