I think if you clarify the details of what you're doing, the management
class assignment of your Archive files will be clearer...

Your posting begins by saying that you have one TSM server; then
suggests that you have multiple TSM servers. And we don't know what you
mean by "I then moved the [TSM] server to the new domain...". I don't
understand what you're doing there. In the context of TSM product
discussions, "server" means the TSM server, and "client" means the node
interacting with that server. When posting to say that you did
something, please quote the command so that we may clearly understand
what was done.

The Admin Ref manual says that ARCHRETention comes into effect when
either of the following conditions occurs:
- The management class to which a file is bound no longer exists, and
the default management class does not contain an archive copy group.
- The archive copy group is deleted from the management class to which
a file is bound and the default management class does not contain an
archive copy group.

The Unix client manual stipulates:
When the server is unable to rebind a file to an appropriate management
class, the server uses one of two values to determine the number of
days to retain the file. If it is a backup version, the server uses
backup retention grace period. Archive copies are never rebound because
each archive operation creates a different archive copy. Archive copies
remain bound to the management class name specified when the user
archived them. If the management class to which an archive copy is
bound no longer exists or no longer contains an archive copy group, the
server uses the default management class. If you later change or
replace the default management class, the server uses the updated
default management class to manage the archive copy. If the default
management class does not contain an archive copy group, the server
uses the archive retention grace period specified for the policy
domain.

See also IBM site Technote 1176515, "What happens to archive objects
when the node is bound to new domain?".

If the old domain definition survives and you didn't perform an Update
Node to reassign the node to a different domain definition, then status
quo.

   Richard Sims