Why dismiss it? TSMC going in for 20% of the foundry won't solve the cash-flow issue, they need "more wallet" to chip in. I'm not arguing it has to be any of the companies mentioned by Reuters, but the 20% TSMC presence is just a guarantee that Intel can deliver their timelines IF they have the money. Bringing some other chip company on-board might guarantee some foundry volumes too.
Anyway, the only sure thing right now is the TSMC story is real, in the sense that they are indeed exploring something. We'll probably have to let it simmer for another few months until we find out if it's yay or nay.