Removing the verification email, besides being insecure, has the same issue.
There’s no way to distinguish between the scenario you’re envisaging and other scenarios on the Wordpress side of things. Even if that were possible, it’d still not be advisable as you can share an invite link without ever emailing it to someone.
So, the auto-redirect to registration may be possible if there’s an update to the DiscourseConnect protocol, but removing email verification is probably not possible (without compromising the security of your site).