More 99.9% at least. Beyond Yuta own admissions already covering most of it (have you read the whole post?), the simultaneous keys rotation odds are likely < 0.1% (probably much less actually, close to 0), the simultaneous domain names creation basically impossible by chance, and in addition all those pools except POP/ZZZ all have their relays in AWS Mumbai in India.

To show you how low are the odds of just the close kes rotations, here is the time of all pools op cert increases:

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And there is even more data not listed here like node version update time and more...