Not sure there is much to worry about it since gm stuff has so much aftermarket support. Lots of options.
There has be some value put on this. If my tranny died today, I can go pull one out of a junk yard the same day for $155 (+$30 core). If my engine died, I can get parts easy, quickly and affordable. I'm wrapping a toyota engine rebuild, it's nearing the cost of a new ls crate motor. If I need parts, I have to go to the 'yota yard or see the russian guy here in Denver.