He is listing APUs, which are a category of CPU, so the CPU cooling is very relevant.
An APU is just a CPU with a good GPU built in. An APU with a really really good GPU could potentially eliminate the need for the expansion bay to be used for a dedicated GPU even for GPU heavy tasks, which would free up the expansion bay for other things.
Leaks indicate that AMD has some upcoming super high end APUs with more than triple the GPU performance of current APUs (almost as good as the GPU module Framework currently offers). But those are expected to have power draws around 120w, or about 2.7x what the Framework 16 is designed for.