In some rare cases we have vote dismissed a number of players (like for pulling extra mobs ahead of tank when we said don't to), and if they were on the same server they PM us telling they have reported us. However GMs have never contacted any of us and we have no warnings. It seems like reports are ignored if there is no verbal abuse, and anything else is covered by gameplay style differences.
Cheating reports are largerly ignored and bots are rampaging for years, unless they are RMT bots which are banned in waves.