Intel is used to dealing with Apple, Google, Microsoft, as well as all of the PC OEM's that are competitors. I'm sure that their experience is being leveraged with respect to staffing to prevent IP contamination in the custom foundry business. I think whether or not Intel is a competitor is relatively minor..
If Intel serves company A and company B, it cannot even accidentally pass along information about company A's designs to B or vice versa. Generally, this means each company's business account at Intel should be staffed by different individuals who are forbidden to interact.
Rikhi discussed at a high level Intel's approach to keeping its product IP separate from that of its customers. He seemed pretty practical in his attitude about knowing the company needs to build credibility as a foundry.