If you're a tech company, and your stack is so tightly coupled to Amazon that it represents an existential threat to your server fleet, you were never going to make it anyway.
Yes, they should have a contingency plan to bring things onto another hosting provider within 1 or 2 days. Anything else is negligence from a business continuity perspective for a company that size.
Companies plan for utilities to go out, which don't even have competition. It's insane to operate just hoping Amazon doesn't get hacked, freeze your account, experience a catastrophic failure, or just decide to quadruple the price overnight.
If uptime has any relevance to your company at all, have (and test!) a process to move everything to another provider in a mostly automated fashion.