Unless you're asking about a change, like, years ago, then, no, the defaults haven't changed in a long time (and it's sadly been a long time since I last put out a release). It is, however, possible that a server admin has overridden the default ball speed values in their config.
You can type "cvar_get ball_speed" at the console to get the current setting the server is using. I think the default is 2660.