WCCF Tech claims DigiTimes got the order size right but that this is for something else. The site points out that TSMC's 6nm node is roughly the equivalent of Intel's 10nm node and writes the Ponte Vecchio GPU is not viable at that node. Instead, WCCF Tech says Intel will be using TSMC's 5nm process for Ponte Vecchio, as well as its own 7nm node.
Here's an overview of what WCCF Tech heard from its sources:
TSMC's 5nm process is roughly comparable in density to Intel's 7nm process and PVC is only feasible at that density level - so 6nm (which is an optimized process for TSMC 7nm) is out of the question. Ponte Vecchio will have multiple SKUs. All PVC SKUs will have an IO die made at Intel. Compute dies will be made either on Intel's 7nm process or TSMC's 5nm process depending on the exact SKU. The Rambo cache will be made in-house at Intel as well. The connectivity die (Intel Xe) was originally intended to be built over at TSMC and will remain that way. Intel did place an order worth 180,000 wafers on the TSMC 6nm process but it is not related to PVC and is part of their ongoing partnership (Intel has been using TSMC for quite a long time).