This is based on proposal from original thread in closed beta forum.
Currently what we have is, that when you get stunned due to being hit, your mouse input to change guard is ignored. This creates those moment where you think you changed your guard, only to get hit by the next attack. It took me some time to realize, this is the reason why I get so frustrated when fighting assassin heroes.
In order to change guard when stunned, you need to either wait until you are not stunned (which is hard), or move the mouse continuously, until the guard actually changes (also hard, not enough mouse pad). Meanwhile on gamepad, you can just hold the stick to change guard and it will change once out of stun.
Proposed change is to remember the latest user input during the stun and changing the guard automatically once the stun is over.
I feel like this would be a nice quality of life improvement for lots of players. Might be even beneficial for gamepad users, as it would help those who prefer to change guards by just tapping the stick once.