Whether the GOS team will support faceunlock is hardware dependent. The Pixel 4a had proper and several cameras with I think infrared and and stuff that made it suitable for secure faceunlock. Later models don't have that which would make faceunlock not secure enough to meet the GOS team's bar. If new Pixels again have suitable hardware they'll support face unlock again. They explained it much better but it made a lot of sense to me.

Fingerprint unlock issues often arise when using screen protection (or ofc with hardware issues), not software related.