The following is official words from MLB - https://www.mlb.com/news/experimental-rules-for-2022-atlantic-league-season
Major League Baseball (MLB) announced two experimental playing rules for use during the 2022 Atlantic League (ALPB) Championship Season. The rules are designed to create more action on the field, to reward athleticism and to raise the profile of starting pitchers.
Double-Hook Designated Hitter Adjustment: The double-hook designated hitter will be modified. In 2021, teams lost their designated hitter when they removed the starting pitcher from the game. However, in 2022, if the starter is able to complete at least five innings, the designated hitter will be allowed to remain in the lineup for the entirety of the game. This rule intends to place emphasis on longer outings by starting pitchers.
Dropped Pitch Rule: As in the second half of 2019, batters will be able to advance to first base on any pitch that is not caught in the air by the catcher, even with first base occupied by a runner. Those who get to first base safely will be awarded a hit. This rule will increase the importance of taking care of the baseball (e.g., pitching with command, receiving, and blocking pitches) and reward athletic players who are able to capitalize on wild pitches and passed balls.
This next section is my own wordings!
In 2021 the ALPB tested some new rules mid season while these will be tested throught the season starting at day 1. Seeing how a lot of players didn't like the new rules from last season it is in their contract to try these out if they like it or not. I will have access to players througout the 2022 season and will be getting updates on how they feel about the new rules they are testing. The season starts on April 21st