Earlier quoted context omitted.
GPUs won't work at all? Can't you even use them for ML/compute stuff?
They don't work at all, there are no discrete GPU drivers for ARM macOS. The cooling solution and 1250W(!) power supply they carried over from the 2019 model are kind of hilariously overkill now, I don't think there's anything you still can install into the PCIe slots which comes even remotely close to needing them.
I wonder if that's a small hint or giveaway of something coming in the future that will make use of it.... One can hope.