Microsoft fixes '19-year-old' bug with emergency patch 12 years ago
Yes, all of our AWS EC2 Windows instances sitting behind an ELB with the latest AWS Security Protocols will not communicate with the ELB after this update.
I was able to fix this by reconfiguring the available cipher suites within IIS. Downloaded the IIS Crypto tool https://www.nartac.com/Products/IISCrypto/Default.aspx and applied their "Best Practices" which removed a bunch of insecure ciphers. After that the AWS ELB and IIS happily communicated.