I guess behind TDE, ML will still create different types of indexes. TDE greatly simplify the task to maintain the indexes.
However, the traditional ML Indexes are not mandatorily reinforced on all the documents in DB. For example, if some documents do not have the xml field, the field range indexes won't index those documents. If one needs to know which documents do not have that xml field, CTS query could be used to identify those outlier documents.
How to do that with TDE? The question is how to know which documents do not have that field? I guess I can not use CTS anymore.