Can't understand why authorities don't catch up to this as "unfair business practice" and/or "discrimination"
In this context it's applying to family relationships. No laws apply. While you cannot pick who your family members are, you can decide not to associate with them for any or no reason. Period.
However, in the US, if they were to instantly "cut off" business relationships, that is, firing employees because they got DFd, or cancelling leases to residential rental property, then I think they would be opening themselves up to religious discrimination lawsuits. However, relationships with subcontractors etc are not subject to the same discrimination laws.
In the past, the "family business" exception was tolerated for almost anything. Elders were to stay clear of determining what constituted "family business". Only if the amount of associated with DFd famly members became an issue in the congregation, then those persons may no longer qualify for privledges -- Elder, MS, Pioneer, etc. but associating with DFd family members could never be cause to DF anyone. If there was no family relationship, that is a different story. One warning, or a brazen attitude about it and YOU'RE OUT!
Surely, evidently, it is reasonable to conclude.... (like that terminology?) this article is an attempt to tighten up on the flagrant association with DFd family and will no doubt be used to strongarm those who "abuse" the exception.