Currently on Quickplay/Competitive.
Mei and McCree can stun a target then hold down left click and headshot TWICE before the stun runs out.
With these changes, they can only headshot ONCE before the stun runs out.
McCree
Flash+ThrowRecovery+Headshots
0.35sec + 0.42sec = 0.77sec
It was reduced from 0.85sec, to 0.7sec.
Mei
Freeze+IcicleCharge+FireDelay+IcicleCharge
0.35+0.8+0.35 = 1.5sec
It was reduced from 1.5sec, to 1.3sec.
So basically buff for tanks only, but nobody plays Tanks, so it’s a buff/nerf for nobody.
Cool, I guess? 
It helps lower HP heroes that are getting healed while stunned.
Heck, a Soldier can even throw down a heal station and selfpeel out of a freeze/flash.
Thanks for these numbers OP
Np, wonder how long it’s gonna take for OWL Casters and YouTubers to notice.
Surely this is a change with the pros directly in mind, maybe even suggested by them? As I doubt many Mei players on ladder do this (high ranks ofc)
When you posted that, did you have this specific thing in mind though (stopping 2 headshots) 
I’m worried about the buff to mobility, I feel like we are just trading one evil for a much bigger one.
It would be easier to double headshot tanks and such then mobile hero’s anyway. Because smaller hitboxes will take longer to line up and we’re talking 0. seconds here
Yeah. Here’s another one from yesterday:
This shouldn’t be entirely true for McCree, because the airtime on the Flashbang delays the stun effect by up to around .2 seconds at range, while he’s “recovering” from the throw.
Well, Tracer is just as dead with a Flash and a Headshot. Since that deals 170 damage.
But Genji and Doomfist are living.
Good explanation. Makes sense. Any thoughts on the Brigitte nerf? Not seeing a similar critical threshold in her case.
The Brig one is just because it’s annoying, and it doesn’t serve much purpose anyways.
To make matters worse for Mei. The damage used to add up to 412.5 if executed perfectly.
This change makes it so Mei can’t combo zarya because you can’t shoot twice.
Huh I got 382, but then I remembered the punch, so yeah 412.
For once we agree on something.
Thank goodness. McCree being able to double headshot a stunned target was dumb.
I know its the noob strat, but what if I flash+fan? Isn’t that still going to grind targets down?