This is one of the conflicts with “associated legislation” in NSW (and I suspect elsewhere).
With regard to Notice Boards, the relevant Legislation is the NSW Strata Schemes Management Act (1996), and Notice Boards have not been compulsory for Strata Schemes registered since the Gazettal of that Act.
However, the NSW Environmental Planning & Assessment Regulation (2000) requires that Annual Fire Safety Statements and their included “schedules” (of safety measures in place) are “prominently displayed in the building” (Pt 9, Div 4, Cl 172).
So…your Strata Manager is right, and you'll need to find somewhere to place a Notice Board – you can purchase small waterproof ones from various suppliers, and if you need to fill-it-up you could include some relevant Strata Info. (like your Strata Manager's details).
Have a look at this link (with whom I have no affiliation whatsoever)
https://www.tandcvisualdisplays.com.au/page/signs_wall_mounted.html)