I know this timeline prefers primary sources and tries to avoid blog posts, but Cloudflare's blog post 'Staying on top of TLS attacks' [1] dated July 11, 2013, was a milestone.

It came in the wake of 'Lucky 13' and the demonstration of RC4 biases exploitable in TLS, and showed the awkward situation that existed at the time: essentially all supported ciphersuites were vulnerable to something, and no mainstream browser supported TLSv1.2 yet in which non-vulnerable ciphersuites were present.

Even if a reference isn't made to the blog post, the timeline should somehow reference the aforementioned ciphersuite conundrum.

[1] https://blog.cloudflare.com/staying-on-top-of-tls-attacks/