Hi there,
the semantic model isn’t really new but has been implemented in late 2018 i think.
you can read about it here: habot and semantics
to me one paragraph is very important:
According to the schema, currently you can only tag an item with one of the Location, Equipment or Point tags, but you can combine a Point tag and a Property tag on the same item.
Tagging works in the (3.x) UI and in textual configuration, also be aware there are more taggings available e.g. amazon/alexa stuff.
AFAIK openHAB is using the Eclipse SmartHome semantics/ontology so the only way to enhance/extend/add tags is to do it on the ESH side…
Regards
T.