Holden is accepting their diagnosis. They are instructing the dealer to rebuild unless there is damage....in which case they would provide new crate engine.
When rebuilding an engine, i'd think many would typically replace a number of parts regradless of their condition, simply as a precautionary measure, may be things like pushrods, lifters, springs, rockers, timing chains, tensioners, etc. I'm not talking of disposable items like YTT bolts and such. I'd think such precautionary parts replacement may be much more important on engines with more mileage but I'm no engine bulder. I'd also expect all parts would be hot tanked as a matter of normal rebuild processes but not sure if that is a given..
Sadly, what we think should be done and what actually occurs with the rebuild may not line up squarely. So it may be worth quantifying what Holden considers will be done during the rebuild process and what the engine builder would recommend should be done as best practice. The views may be poles apart. Just don't assume that because the block is going to a decent engine builder, Holden is paying them to do a job at their usual standard the'd do for a private individual.