I'm trying to game theory out what benefit there is to refusing the premise "No, it's just the OK symbol, don't over react, it makes you look hysterical to people not already embedded in your stupid ongoing twitter culture war and you alienate them by screaming WHITE POWER at them", and... I'm just not seeing where it is in anyones best interests to take what was an obvious troll at face value, even accepting the premise white supremacists did accept the symbol.
Its not like obvious white supremacists are solely identifiable by the use of an ambiguous symbol; at best you 'prove' your confirmation bias, because the people you're mentally categorising as definitely doing this and the people you're mentally excusing as not doing that are people you already have opinions on.