An OCFS2 filesystem residing on a multipath device was nearly full and had to be expanded.
When a size change of a SAN device is detected, the kernel creates some syslog messages, just as when re-scanning SCSI devices for size changes do.
When multipathd detects a size change, syslog messages are created, too.
However when the OCFS2 filesystem is resized eventually, no syslog message is created.

I think resizing a filesystem is an event important enough to be logged.