There is a social institution in some countries where tea is consumed in the afternoon and, importantly, this comes with a societal expectation that work stops during the consumption of tea. The societal expectation is similar to the expectation in the US that most professionals are not available for productive labor between 12:00 and 1:00 because they will be eating lunch.

Thus, when an American company says they're instituting afternoon tea-times, what they mean is they are adding a break to the workday which is not typically present in American companies. When an American company which previously had afternoon tea-time eliminates it, it means that the workers have lost a socially acceptable period in which they were not expected to labor.