If people are keen I would go for one tournament with two categories - traditional and modern. If they end up split along racial lines well so are a lot of sports competitions.
Some people had a related idea but abandoned it under pressure:
To counter this trend, Hardy and his allies want to create a “policy only” space in which traditional standards for debate will be enforced. However, this is nearly impossible to do within the two major debate associations, CEDA and the National Debate Tournament (NDT), as they are governed by participants and have few conduct enforcement mechanisms. [...]
14 schools expressed interest in sending debaters to Hardy’s proposed alternative tournament, scheduled to occur last month. But after word got out that a group of mostly white teams from elite universities were trying to form their own league, Hardy and his supporters were widely attacked on Facebook and other online forums. Ultimately the competition didn’t happen, purportedly because of logistical issues with the hotel venue. Nonetheless, Hardy wrote in an email that a “toxic climate” has precluded even “strong supporters of ‘policy debate’ from “publicly attach[ing] their name to anything that might get them called racist or worse.”
