I think you might be confused?
The origin of the person who created the referral code is not what is under consideration, it is the origin of the person who uses the referral code to install Brave.
If the person who installs Brave is from an Ads supported region, they can be shown ads, they get BAT and Brave gets their share as well. Therefore it’s pretty clear business logic to grow that group.
If the person who created the referral code lives in a different region, for example a Tier 5 region, but the person who uses their referral code lives in a Tier 2 region, installs Brave and uses it for 30 days, the referrer would still get $6.50 BAT equivalent.