Sam Snead liked to see a pause at the top. I believe Bobby Jones liked it as well. On the other hand, Jack Nicklaus was dead against the idea. It's obviously a personal choice. What is important, as Bobby Jones taught, is getting in the position on the backswing where we feel capable, and ready, to strike the ball.
The problem for many of us, especially when under pressure, is that we are in a hurry to hit the shot. We don't complete our backswing, and we often lurch at the ball. I think that pause at the top might be a good thing to try, but only if you can start the downswing smoothly with everything working together.
Then again, what the hell do I know? The Slammer and Bobby Jones like the idea. So there must be some merit in it. Jack doesn't think it's a good idea for most of us. Obviously, given Matsuyama's great play, it works for some. However, the real issue is making certain you get yourself in a position on the backswing where you feel capable of striking the ball as you wish. That, as Bobby Jones said, is the only purpose of the backswing.
I wonder how many Japanese are trying to imitate Matsuyama's swing. It may just become a very popular move if Matsuyama keeps doing what he's doing between the ropes.