The sound you describe is indeed from the throwout bearing. The bearing "runs" with zero clearance when released. A new bearing will spin freely, and quietly at zero clearance, however an old and somewhat sticky bearing will not be driven at engine speed when released (zero clearance), but will instead slip with respect to the fingers of the pressure plate, causing the audible "chirp".

The trans is a G76/18. Fill level is to the upper plug on the right side. ATF