The foundry also needs a Foundry License from ARM [0]. But as has been pointed out, Intel already manufactures SOCs containing ARM cores, in particular the Stratix 10 [1], though Intel isn't listed by ARM as a Foundry License holder. I suspect there are many variations and intricacies to the ARM licensing system that aren't public knowledge. We just don't really know what licensing deal Intel has. For example, do they have a Design license now? If they do, they may well want to keep that private info until they have product to announce.

[0] https://www.arm.com/products/buying-guide/licensing/processo... [1] https://www.altera.com/products/fpga/stratix-series/stratix-...