Invited users miss welcome email by default?

Continuing the discussion from Send email to new users 24 hours after joining:

If I’m understanding this correctly, new users are supposed to get a welcome email of some sort when they transition from trust level 0 to trust level 1. However, invited users, by default, start out at trust level 1.

Is all this correct?

I’m trying to figure out how to get our community guidelines in front of people who are invited to the site early on in the process.