Isn't the usual assumption that team w is responsible for system W to work, team x for system X, etc? And you can figure out who needs to fix a problem when it comes up?
Say W sends a message to Y but doesn't record the message was sent Y or wait for any sort of ack (say a process that drops a flat file to an FTP server that gets deleted after 7 days). Now someone finds out Y is missing a bunch of things. Who's fixing it and who should be fixing it?