I think there is no technical reason that it can’t be supported, it is just because it is not implemented yet. I think it is not implement because:
1. In case of partition plus sorting, it will be like global sort when the query leverage partition pruning if you give partition column in predicate.
2. Partition with global sort will lead to 2 times shuffle in data loading, so loading will be slower.
If user can tolerate these impact and want to use partition for ease of changing and deleting data, I think this feature is welcomed. So feel free to raise JIRA for this.
Regards,
Jacky