DDL operations that operates directly on the bucket namespace will be forbidden. This will ensure that in case of DDL operation on timeseries collection:

• DDL coordinators document will always use the view nss in their coordinator document in case of timeseries collection
• We won't ever need to translate a bucket namespace to its own view namespace. In fact we will always perform translation from the view to the bucket collection.
• DDL can be serialized only on the view nss, thus it can be done before translating the namespace.

In PM-2241 change events are going to be emitted for DDL operations on bucket namespace in order to allow C2C to replicate those on the destination cluster. Thus C2C needs to perform operations directly against the bucket collections on the destination cluster.
To accommodate this exceptional use case, DDL operations will be allowed on bucket namespaces if the client has ActionType::setUserWriteBlockMode authorization over the cluster resources.
(Similarly to what have been implemented in SERVER-67462)