No you don't, but from the way the code is written I bet you did.  In fact that makes me reread the stream_trigger and worry that has a bug, I'll post a comment there relevant to this.  Line 70 can easily be replaced with:

    static const uint8_t MAVStreams[MAXSTREAMS] = { MAVLINK_MSG_ID_ATTITUDE,
                  MAVLINK_MSG_ID_POSITION,
                  ...

etc.  Then in the main loop do something like this:

    for (uint32_t i = 0; i < MAXSTREAMS; i++) {
        // Note: This is tracking the rate for each stream number and not by message type
        if (stream_trigger(i) != 0)
            continue;

        switch(MAVstreams(i)) {
        case MAVLINK_MSG_ID_ATTITUDE:
            // code from below
        default:
            // indicate warning for unsupported message type
        }
    }