It requires an HW upgrade too. I'm pretty confident that they will add FaceID hardware on next MBP 14/16 iteration with HDMI 2.1 while keeping the exact same notch footprint. Easy upgrade to add to convert next cohort of people who are due for an upgrade towards newest models since SoC improvements could be not enough to swallow full MSRP for some buyers.
I think the notch is too big for its current hardware now but it brings a 2-step easy upgrade path for their macbook pro 14/16 besides SoC improvements:
1. Next MBP14/16 : Add face ID on exact same notch footprint. "Amazing incredible most advanced secure notebook unlocking experience on planet Earth" 🤯
2. Reduce notch size or cut it in the long run.