Northern Virginia's Fairfax County public schools have the day off for Diwali, so that's not an unreasonable question.
In my experience, the teams at AWS are pretty diverse, reflecting the diversity in the area. Even if a lot of the Indian employees are taking the day off, there should be plenty of other employees to back them up. A culturally diverse employee base should mitigate against this sort of problem.
If it does turn out that the outage was prolonged due to one or two key engineers being unreachable for the holiday, that's an indictment of AWS for allowing these single points of failure to occur, not for hiring Indians.
Seems like a lot of people missing that this post was made around midnight PST time and thus it would be more reasonable to ping people at lunch in IST before waking up people in EST or PST.
Then I missed it too because I let my Indian coworkers handle production issues after 9,10pm unless the problem sounds an awful lot like the feature toggle I flipped on in production is setting servers on fire.
My main beef with that team was that we worked on too many stories in parallel so information on brand new work was siloed. Everyone caught up after a bit but stuff we just or hadn’t demoed yet was spotty for coverage.
If I was up at 1 am it was because I had insomnia and figured out exactly what the problem was and it was faster to fix it than to explain. Or if I wake up really early and the problem is still not fixed.
I.e. lots of folks that weren't expected to work today and/or trying to round them up to work the problem.