Go read the report...the roof was engineered wrong ..the guys I know at UCFD said there was a serious worry the roof was going to collapse a few years ago when the games were moved. Sometimes just because something looks perfectly good doesn't meant thats the case.
Structural engineer? Been on or above the Freitas roof at all areas, or minimally at ceiling level at all areas, to legitimately assess the actual condition? Perfect shape based on thorough assessments by which unnamed structural engineer?
IIRC, concerns were also raised at some point regarding some components of Freitas' guts. To reiterate, I do not remember the specifics yet seem to recall possible HVAC, ventilation, refrigeration, plumbing, etc issues. Whether that is correct or any of the preceding were/are included in general references to the condition of the building is a different topic TBD.
Don't need to be a structural engineer, just need some basic engineering knowledge. It would be hard to screw up a Butler building design.
You do raise an issue though. The compression system was overhauled five years before Freitas was built and I do not know how many times since. Not sure what the overhaul intervals are for those things or the total anticipated design life. Also not sure about the life of the coolant tubing.
Unless the upgrades being talked about for 2019 start mention the roof, doesn't sound like they are really that worried.
Even accepting your "standard cookbook" take as gospel truth, in what manner does that impact your prior focus on "... maintenance or replace(ment of) the top layer of the roof ..." and current shifting sands away to other possibilities? Or, absolutely ensure the current state of Freitas' roof is good and no repairs are required?