Because the changes she has received.
She was an anti mobility.
We’re always trying to get ahead of the meta and trying to predict what shifts are likely to take place. In this case, we’re seeing some potential for a big tank meta on the horizon, especially with Moira just recently being released and how good she is at healing multiple tanks.
We’ve actually had this sort of meta game in the past and overall it seemed often seemed more frustrating for players than even dive can be sometimes. So as a direct answer to your question i’d certainly be worried about buffing heroes like Roadhog, Zarya, and even Ana until we can get a better gauge on how the game is shifting.
In fact, we’re looking at buffing Reaper and Mei in an upcoming PTR patch (hopefully this week) since they could use a boost and they could help with this meta if it comes around.
But now is she an tank counter.
But reading back does it not shows clearly that they have changed her intented role, so I will retract my statement.
One thing is for certain, and that is that she got buffed to deal with tanks. Clearly is being a tank-counter an intented role. Her slow (and freeze) are her tools for this.