Until now, when Shift-clicking the "delete item" X on the side of the player inventory in creative, all slots (including armor and offhand) would be cleared (that was a useful feature). Now in 19w02a doing the same action only clears the hotbar (which can be done by calling an empty hotbar template out of the stored hotbars anyway)! So I see this as a bug and that feature shall be reverted to its state that it had in 1.13.2.

Thanks