I think the UUID itself might not be that important, except you deploy your VM's using a deployment tool which relies on this id. However, more important than the UUID is the MAC address which is derived from the UUID. A duplicate MAC address will cause issues with networking.
One widespread use of this standard is in Microsoft's globally unique identifiers (GUIDs). Other significant uses include Linux's ext2/ext3 filesystem, LUKS encrypted partitions, GNOME, KDE, and Mac OS X, all of which use implementations derived from the uuid librlary found in the e2fsprogs packeg
strictly speaking, UUIDs only need to be unique among the set of other UUIDs that they might be compared against. If you're generating a UUID to use as a database key, it doesn't matter if somewhere else in an evil alternate universe that the same UUID is being used to identify a COM interface. Just like it'll cause no confusion if there's someone (or something) else named "Michael Burr" on Alpha-Centauri.
i hope this is the answer you were looking for
AS AP states, the UUID in itself is not really an issue, however the UUID and the vCenter ID is used to create the VM's MAC Address, so there is an increased risk of a Duplicate being created on VM deployment.