RCS sub-board regulations

I have a unit. There’s a back and front light. There’s talk of changing the current lamps to something more modern in all the units. This is in NSW. Inside the unit is a switchboard for the unit wiring – a series of circuit breakers; that's all I can say about it, at this stage. The unit Strata manager says, advice from the contractor, is as follows: "It is mandatory to upgrade the internal sub-board from the old circuit breaker system to RCD (residual current devise). We cannot change the fittings unless you have an RCD for lighting. We requested each unit owner text through a photo of their sub-board. It is sometimes possible to upgrade to RCD just for the lighting and not the general electrics, however, the electrician says it is unlikely. The contractor has therefore provided a quote $947.10 (per unit) for upgrade to an internal RCD sub-board. The upgrade of the sub-board would be lot owner expense. If you have upgraded anything electric in recent years (oven, heating etc) the electrician would have been required to upgrade your sub-board." That would be an expensive couple of light fittings. Are there new regs that require/demand that a new sub-board be fitted?

I believe that if any electrical work is done that the board should be bought up to code.