Everyone knows that if (actually when) this change is made it will take time for everyone involved, especially pitchers and batters, to adjust. That doesn't make the change a bad thing. In fact, IMHO a consistent strike zone, no matter how it is defined, would be a good and much-needed change. And I don't see any way to be consistent unless the strike zone is precisely defined.
The current definition of the strike zone, with it being different for each batter, was put in place only because at the time the rule was written there was no technology available to determine the position of the ball as a pitch passed over home plate. The only landmarks an umpire could use were home plate and the batter's body. That is far from ideal because each batter varies in size and stance, because a knee is several inches in height, and because armpits are difficult to see precisely, but it was all we had. Moreover, the human visual system is simply not capable of knowing precisely the position of a pitched ball, but again it's all we had. Today's technology allows us to know very precisely the distance from the ground to the pitched ball, as well as whether any part of the ball passes directly above any part of home plate.
I would be interested to read how, in precise terms, people here think the strike zone should be defined. As for me, I would advocate for defining the strike zone in numerical terms. The width of home plate is fine, and I would also specify the top and bottom of the zone in terms of inches above home plate. I see no good (IMHO) reason that the zone should be different from one batter to another. In no other major team sport does the size and shape of the playing area vary from one player to another and again, I think it would improve accuracy, precision, and consistency of pitch calls.