[cataphract]

The way I read their statements is simply that the it's the binary classification problem (is the user cheating or not) that should be done server-side. There's still data collection going on client-side. Given this, actually sending more data to the client could be helpful because they could use that extra data for cheating, data that a legitimate player would never have access to.

[arcfour]

Well, the end-goal is to stop cheating, not to detect it - detecting it is simply a means to an end. In that sense, sending more data is not ideal because even though you might be able to detect cheating more easily that way, cheaters would still have some period of time where they are able to cheat (and cheat more easily), thereby worsening the experience for legitimate players.