There is no way Apple designed the R1 from scratch, it will contain a bunch of components from their other SoC designs. Obviously it's going to have quite a few

There is no way Apple designed the R1 from scratch, it will contain a bunch of components from their other SoC designs. Obviously it's going to have quite a few more IPUs than a standard SoC, which only have to handle ~4 cameras. It also clearly has the display scan-out components. And it's entirely possible that one of the components Apple took from their grap-bag of SoC component is the GPU compute cores. Properly not the rasterizer or texture samplers, but I could see the compute cores being useful for running tracking algorithms. The massive amount of memory bandwidth does kind of suggest GPU compute cores. But even if it does, that doesn't make it a discrete GPU. Just a dedicated SoC with some GPU components, and a bunch of other things. But it simply can't be used as in indicator of discrete GPUs in Macs, because all those other SoC components would be a waste of silicon and it's unlikely Apple would reuse the R1 die as a dedicated GPU.