The operator doesn't propagate table to the new replicas if the table is in a replicated engine database. See

I guess the reason is all table schema will be propagated automatically as those tables are in a replicated engine database. So there is no need for operator to create tables on new replica(s) in the same shard. But in the case of expanding shards, none of replicas in a new shard has any table, which can be propagated to other replicas by CH.