In an attempt to balance Overwatch, developers are testing out some changes in the experimental mode, but as the player-base has noted on different channels the game will not be balanced. It's not all gloom and doom though, since developers Geoff Goodman and Josh Noh explain in an interview on Overwatch's official news page that creating a perfectly balanced game might be impossible.
For context, Noh is a grandmaster/Top 500 player that has been giving Blizzard feedback since 2013 until becoming a game designer on Overwatch in 2018 whereas Goodman worked on Project Titan and was later moved to the Overwatch team. This gives them the perspective of a skilled player, and how changes to heroes can be used at high-level play (as the years progressed, more additions ranging from Overwatch League players, streamers, and content creators came along according to Blizzard Entertainment).
Josh went on to explain why he does not believe that "a perfectly balanced game doesn't mean it will be fun."
"Design something fun and then balance it, it’s often more difficult the other way around. Perception of balance can be more impactful on the state of a game than the 'true' numerical balance. This is especially true in competitive team games as social pressure is a significant factor. Be aware of your own biases when analyzing things. Put the gameplay and player experience first."
Geoff added that it's true of the heroes since each gameplay reflects the personality of the hero being played. He points to Widowmaker, Tracer, and Junkrat as examples. Widowmaker "feels slow" while Tracer is "fast and snappy" but then Junkrat is "pure chaos." When it comes to balancing, they can't change the kits so that they are more or less the same--each character is so different from one another, that the gameplay should reflect that even if it leads to a slower character feeling weak against a fast one.
While some heroes, such as Doomfist, did not receive any changes, we are bound to see the meta shift a little even if the numerical difference is a small one. In the meantime, feel free to read our overview of the Experimental patch notes while looking forward to a sequel and mobile version of Overwatch.