A police officer who previously participated in the Illinois Municipal Retirement Fund (IMRF) for service as a member of the police department of a municipality and was transferred to that municipality’s police pension fund upon its creation under this Article shall, for the purposes of determining the applicable tier of benefits under this Article, be deemed to have become a police officer and member of that municipality’s police pension fund on the date that he or she first participated in IMRF as a member of the police department of that municipality, notwithstanding whether that start date was before January 1, 2011.