I think it's a fab play. Deny TSMC a customer while at the same time getting Altera to fill up some idle Intel capacity.
Also what I have thought, but Intel would do better to simply provide the best foundry offering instead of buying each customer. Yeah, I know, officially they are claiming it's all about their cloud business. I don't believe a word of this. This is going to be a niche market that can already be well served with PCI Express attached FPGAs. I don't see a need for tighter integration for such a niche.