Yes, yeloww jacks can be predators.
They  search for both, sugars and meat. Sugars are the principal food for
adults and proteins for larvae. Wasps can enter hives and steal honey when
colonies are weak to cover all the stores when weather is cold. They fly
round the hives searching for any dead or weak honey bee (worker or drone)
which they kill and cut into portions. Those parts of the bee body
containing muscles (thorax) are then brought to wasp nests and fed to
larvae. This activity would not be dangerous for bee colonies. On the
opposite this is an useful sanitary cleaning of the nearest vicinity of
hives. But if there is not this kind of prey enough larger species of
vasps (Vespa, Vespula) attack honey bees at the hive entrances and kill
them. In the battle between bee and wasp the latter usually is the victor.
It cannot be excluded that wasp can transfer bee diseases among hives.