It just seems really unprofessional to me. I mean, in major sports you frequently have brothers/sisters playing against each other in major finals and these organizations don't fix the seeding as a result. Venus VS Serena Williams @ Wimbledon, the Grobowski brothers in the NFL, etc.
It's like someone mentioned previously, even if Reginald's brother wanted to throw the match, he still has four other people on his team that would be PISSED at him who still want the $100,000. Moreover, it seems pretty ridiculous to changes the seeding based on suspicion alone.
Moreover, with the current seeding, Epik will now face Solo Mid later on in the tournament, which has even bigger ramifications if one team were to throw the match.