I think we're talking about different things here.
This isn't automatic mitigation, it's only about the necessity of revocation after the comprising and fixing have been detected.
You're not leaving the system "compromised for 6 days", you're doing whatever you need to do to fix the compromise, and then can restart. Your new system will be safe & sound right away (provided you've actually fixed your hole). The only thing that will happen, is that there will also be another, older key for your domain in circulation, under somebody else's control. If that's a problem, i.e. your continued (new) system security, is sensitive to that, you need to stay put & keep the system disconnected until the old key expires.
But then again, having had the ability to revoke wouldn't have helped you much anyway. Typically, once you fix your hole, it's not your system that's at risk by the existence of the old key, it's your customers'. And it all would've depended on them updating their revocation lists timely - which they probably weren't to begin with.
And if you weren't going to fix your hole, then you would've been an idiot to begin with, and revocation of the old key does shit, because once you do that an set up a new one, that one will have been compromised, too.
And if you wouldn't have found out that your key (and system) were compromised in the first place... well, the nee 6-day regulation helps just about as much as the old 90-day one, namely not at all.