Zhang Jike brushes, but brushes so lightly that he barely touches the ball.
If you watch closely, from the slow motion angle, the ball passes the end-line and takes a sharp turn in the other direction in mid-air that looks almost like a V. The first bounce after the contact with ZJK's racket is on the top of the edge of the table. Zhang Jike misses good contact but he brushes the ball so delicately (not his intention) that it changes the flight of the ball. There is no way a serve can pass the end-line by 3-5 inches, and just turn around and go the other way at that sharp an angle in mid-air. If they had a camera angle where you could see ZJK's bat face, everyone would be able to see clearly that his racket just barely grazes the ball. But you can still see this: where the ball changes directions, the ball his hidden by ZJK's racket as it swipes past the ball. The change of directions looks very different than those short slow serves that change directions on the bounce. And most of those short serves bounce several times before changing directions. Also note, in the video where Ma Lin is practicing serves and you can see the ball changes directions, the change of directions happens on contact with the table. The contact with the table is how the spin causes the change in direction. They could not change directions in mid-air after the end-line.
This does not take away from the fact that Ma Lin's serve was great and had enough spin to cause Zhang Jike mishit and miss the contact he wanted and barely touch the ball.
I have actually done this myself where I brushed but misjudged where the ball was on a long heavy serve and had pretty much the same result.
Just watch the video again and freeze the frame just after the ball passes the end-line and then watch the angle it changes directions at. You can see it. The contact is there. It is just too light to make a shot. And because of the camera angle, the contact is blocked. But you can see that where the ball changes directions is when the ball is hidden by the racket swiping past it.