Another demonstration of the fragility of blockchain analysis.
While I realize you just meant it as a light "fun fact", I think it's worth pointing out that walletexplorer is very primitive and semi? unmaintained -- and you won't be able to trick any serious analysis tool with a coinjoin like that. [Although coinjoins can do an amazing job at tricking them! But you really need the coinjoin to look like a normal transaction for that]
You're right that is fairly primitive but many people still use it and it has some influence. During the QuadrigaCX exchange hack affair in early-2019 some people used walletexplorer to find that exchange's hot wallet, some of the transactions go to and from the CoinJoinMess cluster (which then was called MtGoxAndOthers). When this was found a bunch of people were posting that QuadrigaCX was receiving money from MtGox(!) They carried on until they were informed that it's only the coinjoin cluster.
I wouldn't say its completely trivial to detect that something is odd with the coinjoin bounty payout. The inputs use multiple address types, but Samourai wallet and Bitcoin Core also sometimes do this so it's not evidence of non-coinjoin behaviour. Also there are many equal-valued outputs, but the transaction doesn't match the style of JoinMarket or Wasabi transactions (there are far more equal-valued outputs than inputs for example). It would definitely be interesting to see what the more developed tools say about it.