Nate Nanzer the commissioner of Overwatch League took to Twitter to announce that Stage Four will be played on patch 1.22 here are the details.
Here is the statement from Nanzer:
Recently there’s a been a lot of discussion as to which patch Stage 4 of the Overwatch League will-and should-be played on, 1.22 or 1.23. The league and the developers share the goal of Overwatch league play being on the latest patch possible, with certain exceptions. One is if it would be unfair to introduce a new patch mid-stage, in the heat of competition. That’s why the patch that reworked Mercy, which went live in Stage 1, didn’t appear in Overwatch League until Stage 2. Another reason is if we feel a new hero, or significantly reworked hero, hasn’t been available for our teams to practice long enough in advance of the start of the stage.
Tournament stability is a third reason. A potential bug exists in patch 1.23 which inhibits the ability to accurately resume play on an escort map should a pause or disconnect occur. (It should be noted that the Overwatch League version is distinct from a live patch.) The developers have been working hard to find a fix, in time for Overwatch League players to prepare, but thus far they have been unable to do so, to the degree of certainty that we require for the league. As such, given the paramount importance of tournament stability, Stage 4 will be played on patch 1.22.
Fan reactions have not been kind. However, it is good to hear Blizzard send the message and explanation. Rough timing with Stage Four starting tomorrow.