Looking through my catalogs from '89 to '91, I see the threaded holes in all Mondial, Superleggera and Giro frames. I also think I see them with the Campione D'Italia models. I had one from this era and seem to recall it had the eyelets.
Looking back, it's surprising to me that Bianchi was using Gipiemme dropouts and didn't ssem to ever use Campagnolo.