Hello all
The definition at dcterms:modified is "Date on which the resource was changed".
Since there is no article specifying "Date" and no cardinality constraint, some people interpret it as "a date" and some as "the (latest/last) date".
In LOV curation, we find vocabularies with multiple values of dcterms:modified, which rely on the first interpretation, but we see also for example RADion at
http://www.w3.org/ns/radion#dcterms:modified saying :
Definition The dcterms:modified property fully represents the RADion property Date of Last Modification.
Usage Note RADion uses this to provide the date of latest update of the Repository, Asset or Distribution ...
... with a majority seeming to opt for "last/latest".