Domains can be started disruptively or non-disruptively. It depends on the type of change your making and whether the current domain ID is 'preferred' or 'static'.
If it is 'preferred' then you will need to invoke a disruptive fcdomain restart for the new domain ID to take effect. When you perform a disruptive restart,
reconfigure fabric (RCF) frames are sent to other switches in the VSAN. This forces ALL devices in the VSAN to be logged out. It is indeed disruptive to the entire VSAN.
If it is 'static' then you can invoke a non-disruptive fcdomain restart for the new domain ID to take effect. When you perform a non-disruptive
restart, build fabric (BF) frames are sent to other switches in the VSAN. This DOES NOT force all devices in the VSAN to logout. So from a VSAN perspective, it is non-disruptive restart. Of course, the FC devices directly connected to the switch with the changed domain ID must be disrupted because they will need to get a new fcid. So the switch sends them a Fabric Logout request (FLOGO). They will get the new fcid when they FLOGI again. The key point is all the other VSAN members on the other switches will not be disrupted. They will just get an RSCN frame (not an RCF) to inform about those devices that rejoined the fabric with new fcids.