If we do not want "Theme Updates Induce Panic Attacks”, Theme Check Team should be more flexible. One thing comes to mind - do not force old themes to comply with the new rules that are not required for the security.

In my example I have two themes with about 13K users. Now I was basically forced to change the text domain. Themes had numerous updates and suddenly I cannot submit update because there is a new rule, that requires text domain be the same as the theme slug. I was told that it is required for the new integration with translation service Glotpress, that I actually do not even use. I was also told that if I will not comply, theme may be dropped from the WP.org in the future.

So let's imagine what will happen for the international users after update - some fields will not be rendered in their language. Now it basically means that every one using a child theme (who cares if they have skills...) will have to go through functions.php and other files and change the text domain.

It is sad, but that's the price to be listed on WP.org...