It’s always tricky. I understand the thought that it was unfair to be killed by Sombra while your healers were asleep. But on the other hand, there’s nothing more frustrating than being pulled out of invisibility because someone could see or hear you.
The idea itself is extremely good, but it would be necessary to ensure that players couldn’t just adjust their sound settings to hear Sombra’s footsteps well.
Also, Sombra is currently (as usual) very weak in comparison. This would mean that your nerf would need to be balanced elsewhere.
Audible footsteps in stealth/invisibility will no longer be interrupted by damage.
The idea is that it will be very hard to hear at all during a brawl on point, while it will be more realistic when you just come from spawn and makes spawn camping harder.