You'd have to wait for a lawsuit for this kind of thing to come to light. Deals like this could be concealed in incentive tiers across products. Say, you buy 1M WP7 licenses for your future phones and you enter a tier where your Win7 license cost decreases enough to offset the cost of the WP7 licenses, plus a small incentive. Your WP7 licenses came, essentially, for free and they can brag about how OEMs are enthusiastic about WP7 and how that dooms the iPhone 5 or whatever other MacGuffin you choose to attract media attention.
That could be true, but it's basically idle speculation at this point. It's like accusing someone of murder and when asked for evidence, stating that the evidence will come out when the person is interrogated. Eh?
Samsung buys 10M OEM licenses for Windows7 for netbooks and MS throws in 1M Win7 phone licenses for free to make it's numbers look good.
It's like newspapers handing out free copies to hotels to boost their circulation figures.