no more "Excluded route names" ?

Correct. Nearly all exclusion and inclusion rules are now based on condition plugins. You can install the https://www.drupal.org/project/route_condition → module to include or exclude specific routes.

Great, thank you very much @robphillips →

You can install the https://www.drupal.org/project/route_condition → module to include or exclude specific routes.

For anyone coming here unsure what the steps would be:

1. Add and install the route_condition module indicated above
2. Visit the "Require Login" configuration page (/admin/config/people/login-requirements)
3. There will be a new section for "Routes". To replicate the funtionality for "Excluded Routes" from version 2 of "Require Login," tick the "Negate the condition" checkbox and add whichever routes you previously excluded.