Can't comment on these kinds of parts in Aerospace industry but Porsche are using this 3D printing technique.
They have been re-manufacturing parts that have been out of stock for a long time and for which the original tooling is worn out.
Such parts include clutch-operating levers and even pistons for their top sport models using, IIRC 'adaptive-laser-fusion' tech both of which would be high-stress parts, so I can't see why fan blades would be too far of a stretch .