As shown by the pro level the buffs Widowmaker got made her able to function both with and against dive due to the shorter cooldown on her grapple which made her able to consistently escape when being dived unless the diver was a very persistent Genji.
Combine with Hanzo’s new power and he would slot right into dive as well as against it since he can melt the dive tanks easily. In fact at the pro level that is already happening even though they have old Hanzo.
Also shown by the pro level is that even swapping to Brigitte is not a sure thing, as we have been getting more matches where the Brigitte is unable to stop dive and only blunt it a bit. Furthermore this is also being shown by some of the more adaptable tracer player content creators they have developed tactics for how to play around a Brigitte and abuse her when she is on cooldown.
She may be good at dive, and is a dive counter, but is not a silver bullet pick this and dive is useless mega hard counter.
Which is part of why she is falling out of the meta and double sniper is steadily taking its place. The same meta that has been developing on the pro level even with old hanzo.