3 years is quite a short horizon when it comes to semiconductor fabs. Also this article is a dupe, when it was previously discussed it surfaced that after some time either party can cancel with only 90 days notice.

No its not.

"Both SpaceX and Google have the option to terminate the agreement with 90 days’ notice after December 31, 2026"

They know allocation they have from TSMC for TPUs production they know allocation they have from Nvidia they see demand curve.