Like anything these days, rules and regulations can change at the drop of a hat. It's up to the owner/builder to constantly keep up to date, and on top of these changes. Many engage in regular contact with their certifier to give them the updates, and the vehicle should be regularly checked by the certifier to make sure that it meets the rules and regulations as the build progresses.
I think that if your vehicle is legal, you shouldn't have anything to worry about.
However, it is unfortunate for those who are half way though a build and the NSW RMS decide to cease any future approval of ICV's with no prior warning given. I have a mate who has just invested a substantial amount of coin in introducing a new type of ICV into the market. It's a major investment in tooling etc. and they are unable to get approval. He's not happy, and I don't blame him for being upset with the NSW RMS.
Hopefully they can get through it.
With the other modded cars out there, there was prior warning that the ECV's as they were previously known, did have a life span on them, and that unregistered vehicles will require re-certification to bring them up to date, and n line with the new regulations.
Let's face it, there are many cars that have been previously modified and registered under the old ECS scheme, and have since been re-modified, or further/majorly enhanced/changed, which would now render their previous engineers report defunct/irrelevant.
It's just a matter of getting all the heavily/modified cars safety levels up to date, and in line with today's standards.
Remember guys, Safety is paramount here!
Al