Apple's in-house chip lineup based on ARM's cores that currently includes plans for laptops and possibly workstations will soon be expanded with discrete GPUs made on TSMC's 5 nm node. Based on the iGPUs found in the Bionic SoCs, these discrete GPUs are codenamed Lifuka and are expected to first release on next year's iMacs. Apparently these new dGPUs will replace AMD's lower-end solutions, but team red will still provide professional models for the Mac Pro workstations.
https://www.notebookcheck.net/Apple-to-drop-AMD-s-lower-end-GPUs-replace-them-with-proprietary-5-nm-GPUs-by-2H-2021.490495.0.html