The trade off that came about in the I-codes that eliminated some of the requirements in the legacy codes are predicated on if you have the current required sprinkler system installed
2012 IBC
[F] 903.3.2 Quick-response and residential sprinklers.
Where automatic sprinkler systems are required by this code, quick-response or residential automatic sprinklers shall be installed in the following areas in accordance with Section 903.3.1 and their listings:
1. Throughout all spaces within a smoke compartment containing care recipient sleeping units in Group I-2 in accordance with this code.
2. Throughout all spaces within a smoke compartment containing treatment rooms in ambulatory care facilities.
3. Dwelling units and sleeping units in Group I-1 and R occupancies.
4. Light-hazard occupancies as defined in NFPA 13.
3401.2 Maintenance.
Buildings and structures, and parts thereof, shall be maintained in a safe and sanitary condition. Devices or safeguards which are required by this code shall be maintained in conformance with the code edition under which installed. The owner or the owner’s designated agent shall be responsible for the maintenance of buildings and structures. To determine compliance with this subsection, the building official shall have the authority to require a building or structure to be reinspected. The requirements of this chapter shall not provide the basis for removal or abrogation of fire protection and safety systems and devices in existing structures.
You need to find out what the adopted code was at the time of construction and follow that if it is more restrictive. We do not allow the removal of rated doors or closures in older buildings just because there is a fire suppression system in place. They have to prove the fire suppression system meets today's code requirements.