Let us hope so. I had a Fiat that rusted through an exhaust manifold. That was 45 years ago, and the car was used when I bought it. Maybe -this- cast iron is thick enough (seems to be plenty thick) that it will not burn through.
I also see that the air conditioning compressor mounting bracket is cast iron, and well-rusted. That I don't care about as much, as it seems beefy enough for the load with the design of it. Lots of I-brace designs in it.
Anyhow, I agree it is not a big deal.
Because at least an exhaust manifold is a small and easy to get to thing ( at least the one in the front of the vehicle is, can't say about the back Bank 1 manifold ), and once you have the new part, can't take but an hour or so to replace each one.
I'm certain the heads are of no concern whatsoever, due to their massive design.
Lg