Great way for MLB to test conceptual improvements to the game without needing to get player association buy-in nor owner buy-in first. If successful in the Atlantic League, it makes it easier to support changes in the majors and minors. Much better way for Manfred to test the things he wants vs. unilaterally implementing things like pitch clock without player association approval.
I would like to see the Atlantic League test how a shortened count (3 balls for a BB, 2 strikes for a K) would work for hitters and pitchers and how much it could speed up the pace of game. Similar to how baseball went from a 5 balls 4 strikes count in the 1880s, the game needs to get faster to keep the younger generation involved. This kind of a change affects both pitchers and hitters which provides some balance.
None of the changes currently proposed or contemplated would have a similar affect on the pace and time of the game as shortening the count. In simple theory, the game time should be shortened by 25-30% by a shortened count which could mean as much as an hour of time savings on a 3 hour game. Of course, this time savings could be negative for TV contracts but if it increases viewership because of a faster pace to the game, then perhaps there wouldn't be any negative impact.