Shift selected Zone(s)/Group(s) Right (Zones incl. Root Key) ⌥⇧→
Changes the root key when moving a zone. Unchanged from the EXS24 in function. Visual interface changes abound.
Graphically edit Logic Pro Sampler zones and groups — Apple Support
You can edit zone and group parameters numerically in the Mapping pane zone view and group view. You can also graphically edit a number of zone and group parameters in the Mapping pane keyboard view and the Zone pane.