A couple points of reference:
- 2023 G20 3 series LCI Facelift was announced May 17, 2022 with a U.S. market launch of July, 2022.
- 2022 X3 / X4 LCI Facelift was announced June 8th, 2021. Production began in August 2021.
- The E89 Z4 LCI Facelift was announced December 17, 2012 and began production in March 2013. However, these cars were actually 2014 model years.
Historically it seems like production begins two months after announcement. I'd say that it is possible they announce the LCI in September and production begins as early as November. They could also do a repeat of the E89 Z4, and announce it in December as a 2024 MY.