I figure the main benefit in the short run is that they wouldn’t need to rebalance offtanks. And if they need to change Mei 350hp, 100selfheal, 10sec wall would work.
Then can add more heroes later if they need to.
You are basically suggested getting rid of the need for barrier tanks. Which almost certainly isn’t going to happen this year.
Launch Sigma was actually pretty strong, and Orisa could be stronger as well. But worst comes to worst they could just up their barriers/hp/firepower by a couple percent every week or so, until it’s good enough.
As for faster balance changes, I practically designed the concept they are using.
Unlike changes to OVERWATCH.EXE which takes weeks of testing and certification, they could make changes to SERVER_SETTINGS.INI every 5 minutes if they wanted to.