Back to topic:
While I agree that being vulnerable is not the same as being attacked, I still have a hard time understanding why you seem to be downplaying the significance.
First of all, I don't have to prove anything, all the papers that describe actual explotable TLS vulns over HTTP and SMTP/IMAP equally applies to Emacs if you've ever downloaded something over HTTPS or login to a server say Github via an API package like ghub.el. Email is worse with STARTTLS, although the attributes are different. SMTP/IMAP connections tend to be much shorter and less frequent, so your area of exposure may be smaller> But since emails tend to contain a lot of vital PII, the actual harm is probably greater than knowing your session cookie for a blog. Losing email credentials is also quite devastating.
Second of all, TLS is mostly used to guard against all kinds of MITM attacks. There are some kinds of MITM attacks easier to carry out than others, and they don't have to be targeted. Logging into your email account using a coffee shop's wifi without checking for known vulns before tranmission of TLS records doesn't sound very comforting to me.
Security, most of the time is about prevention rather than mitigation after the fact, just like you would wear a seat belt even though your likelihood of dying in a car crash isn't very high. Am I supposed to be not shocked to discover my car comes with a seat belt made out of a thin piece of printer paper?
P.S Since we are putting out credentials, I used to work at Cloudflare, not that I was in any security or systems engineering capacity, but I have also been quite interested in security issues. I guess that makes me a "security-hobbyist".
//edit after your edit
You probably should stop accusing me of accusing anybody, that's the exact opposite of what I have done. Please read the last link in the article (https://lwn.net/Articles/759460/).