Here's another tought. Looking at the groove patterns on drivers, most of them do not have grooves in the centre but have them on the sides. Untill now I never asked myself why this is. Grooves increase spin and on a driver this means loss of distance. So this makes sence to have no grooves on centre hits, but have them on off center hits that will go to the left or right. Add some extra spin and loose distance on purpose on errant shots to limit the damage hitting the ball into the woods or deep rough.
3 woods especially hitting them from the deck require grooves and spin to get the ball airborne, so grooves on 3 woods in general cover the whole clubface. What if Matsuyama wanted added spin for his off-centre hits to have the same damage control as on a driver and added roughness to the face for that purpose? No harm in doing so as long as one does not exceed the limits set in the rulebook on the roughness of the hitting face.
If the markings were purely an alligment aid, IMO they would have been done with more care and precision.
