Mr Zuckerberg cited a study showing new employees that started as remote performed more poorly. Does anyone know if the level of new hire training and onboardi

Mr Zuckerberg cited a study showing new employees that started as remote performed more poorly. Does anyone know if the level of new hire training and onboarding is the same? My experiences with onboarding is you generally sit with someone for a week, all day - and sometimes for two weeks. Usually the productivity hit of doing this is swept under the rug. When working remote, are managers still designating mentors? In places where this happened unofficially, does that style of onboarding still happen?