... which is what happened with GPU's with TSMC. Apple bought all the capacity for the first 6 months, and delayed everyone else from getting any silicon baked.
I'm actually not so sure about that. See, desktop GPUs are necessarily very big, whereas mobile SoCs are comparatively rather small. Big = expensive, especially on a new process, and doubly-so, if yields aren't great. So, I think it wouldn't have been economically viable to fab GPUs at 14/16 nm much sooner than they did. And even now, Nvidia is still struggling to meet demand (due, in part, to yield problems... or so suggests semiaccurate, on the free side of their paywall).
Now, regarding Intel's 10 nm... let's keep one thing in perspective, here. As far as I'm aware, Intel is still in full control of its fabs. I think it's safe to assume that no one is going to prevent them from using their own fabs as and when they deem it strategically valuable to do so.
And, they've been fabbing others' chips, for a while. So, it's not even like this is an entirely new situation.