Microsoft's containerization strategy heavily depends on Docker (they've got a licensing deal so that Windows server can use Docker EE for free) they might well pay good money to by Docker
Didn't IBM just buy Red Hat for $34 Billion? Can you imagine a future where Amazon acquires Docker to optimize it to run on AWS and perhaps perform a bit worse on GCP. Any small advantage you could get in the space would equate to large changes with as ubiquitous Docker is and as large as AWS is.
Perhaps but given AWS is a heavy Xen and KVM shop something like Kata Containers might suit them better.
I can think of a few companies that may pay an absurd vaulation for Docker; IBM and Microsoft.