It amuses me that your code only checks the first letter. So, if I were to write
Code:
sm_suppressconvar mp_restartgame do
it would disable mp_restartgame's reporting.
Having said that, I wasn't aware that there was a server_cvar event.
It seems like a lot more work to hook server_cvar and do it there rather than just stripping FCVAR_NOTIFY from the cvar, though...
Edit: Also, I'm disappointed to see a plugin approver reusing the same string buffer for three different arguments in the same function. While you could argue it's efficient, it's very hard to maintain later.