That'll sort itself out pretty quickly. TSMC is flush with cash from the premium pricing they've been able to charge for their 5nm fabs. Every day TSMC doesn't have enough capacity is a day they funnel easy money straight to their competitors at Samsung and Intel.

Investing into increasing their fab capacity is the easiest business decision they'll ever make. And if they need finance they could get investors lining up around the block throwing money their way.