I'm the author of the Tweet which this paragraph links to. The author of this blog post is misinterpreting the problem. It's not the session ticket which is rotated after 6 hours, but the session ticket encryption key (STEK). This has nothing to do with the length of the TLS session, but rather the lifetime of the process using GnuTLS. For the first 6 hours, connections made to the GnuTLS server are vulnerable. After the process has been running for 6 hours, new connections are safe (assuming there's no other GnuTLS vulnerability). This reduces the impact of the vulnerability considerably (although it's still really bad).
> It is likely that people don't have OpenSSL in mind when they suggest moving away from GnuTLS
No, OpenSSL is exactly what we have in mind, including Filippo: https://twitter.com/FiloSottile/status/1270130358634283008
OpenSSL isn't perfect but it has improved considerably since Heartbleed and has the resources (funding and competent people) that a crypto project needs.