Literally the only masterwork xbow/bow items that got a damage buff are the low tier bows (which got an overhaul in general) and some of the cut damage arrows. All the masterworks we're used to (MW crossbow, MW arbalest, MW heavy xbow, MW horn bow, MW rus bow, MW longbow, MW bodkin arrows, MW steel bolts) have no change to their base damage.
I can't wait to see how many more people start whining about how ranged damage got buffed when it actually didn't.