Deleting a Drupal 8 Content Type Field also Deletes all the Views linked to it... Undo? So I deleted a Drupal 8 content type field and it also deleted the views that is associated with it. Is there an undo button?
Yes, that's what currently happens. Drupal informs you on the delete confirmation page what all will be deleted.

You can try one thing that to restore your backed up database.

Also, there is an issue that tries to improve it so that the view updates itself instead.