For Debian 10 Buster
Confirm version of curl frozen
Check to see if there is a newer version of tls supported in curl manpage
https://curl.haxx.se/docs/manpage.html
If so:
grep Whonix code for --tlsv1.2
https://github.com/Whonix
update
https://www.whonix.org/wiki/Template:Curl_Secure
Duplicate/Re-tag/Close&Create ticket for next Debian version.