It appears that Intel’s announcement to approach third-party foundries has come well after the decision was actually taken internally. As per sources, Intel has already reached an agreement with TSMC wherein the latter will reserve a significant chunk of its upcoming 6nm capacity for the former.
At the moment, it’s hard to tell whether TSMC will fab just the Ponte Vecchio HPC GPUs or consumer Xe GPUs as well, but 180K seems a bit too much for the HPC market. I reckon it’s likely both while CPUs will continue to be manufactured at the chipmaker’s own foundries.

TSMC’s 6nm node is an enhanced version of the 7nm process, similar to Samsung’s 8nm which will reportedly power NVIDIA’s consumer Ampere lineup.
The photomask of Intel’s Xe GPUs has reportedly been redesigned to comply with TSMC’s 6nm process and the production will start next year itself. Meanwhile, rival AMD has further expanded its 7nm stake, becoming TSMC’s largest client for the said node by doubling 7nm/7nm+ orders for 2021. The company’s Zen 3 based Milan and Vermeer CPUs will expected to land later this year along with the RDNA 2 graphics cards, all based on the 7nm+ process.
Investor concerns regarding the impact of Huawei’s ban on TSMC’s 2021 revenue have also been quelled as the foundry’s high-end processes have been fully reserved for the next year thanks to the combined orders from Intel, AMD and Apple.