Considering how Intel doesn't tend to hold grudge-matches with their customers, I seriously doubt there was any risk in the first place. If TSMC yields were too low to mass-produce Apple Silicon, they could easily ship out another copy-paste Macbook iteration with Magic Keyboard and nobody would care what chip it had inside.

With the benefit of hindsight, it feels more like Intel and Apple were in a race to see who would outsource the Mac chip first. Since Apple already had the supply chain set up for the iPhone, cutting Intel out of the equation was mostly just a matter of designing an SOC. They took the opportunity, and now we're seeing Intel glumly admit that they too can be energy-efficient if they swallow their pride and pay TSMC.