What’s a Hero Pool you might be asking? Based on it being summer and all we wouldn’t hold it against you to think that’s it’s a physical swimming pool where Tracer, Winston, Mei, and others go to cool off. Building off of the recent map pool, which limited players to certain maps, the proposed Hero Pool in Season 21 will disable heroes week-to-week for Competitive Play. A bold move and one that the Overwatch team admits may not persist, depending on how it performs.

That said the reasoning is solid – that being to allow the meta to change from week to week and create more diversity in team composition. According to the announcement the decision of what heroes will be there to select or not there will be handled by the design team and it will be closely monitored to see if the Hero Pool rotation needs to be adjusted via extending the time or reining it in right down to a particular match.

This will affect Overwatch League competition too with Hero Pools set to arrive in the 2020 season. According to the announcement, "Starting March 7, the Overwatch League will make one tank, one support, and two damage heroes unavailable for selection during matches each weekend". In addition to this Blizzard plan to shorten the time-frame between when a patch goes live to when it might appear in an Overwatch League match.

This leads into the next major change coming, related to balance philosophy, and that is the introduction of an Experimental Card across all platforms – including console and Nintendo Switch. Available on the Play screen this will allow the designers to test new changes and balance ideas separate to the PTR system. The team plans to use this as a basis to test potential new system changes that may or may not end up in the live game. The Experimental Card will join the current roster of modes in Overwatch with progress towards Loot Boxes still counted.

Patch 1.45 is also set to beef up anti-cheat efforts and is expected to go live next month. For more, here's the latest Developer Update video where Overwatch Game Director Jeff Kaplan discusses the changes.