How many large tech companies do you think can do that? Each service wants to benefit from the use of other services. Ensuring there aren't dependency loops in this complex graph sounds tricky.
The best way to avoid this problem is to have a secondary datacenter that is hot, and to never let both fail. Of course, this is what twitter is doing. Designing a DR plan where you can lose multiple primary/secondary datacenters is hard enough that basically no one does it.
This is something that really doesn't belong in the whistleblower complaints because it wasn't under his responsibilities, twitter wasn't lying to anyone about having properly implemented DR plans, and twitter's DR plan isn't out of the ordinary across the industry.