I agree that these are the most likely reasons, but both seem rather outdated to me.
On the subject of secrecy, most other nations (US, Russia, Japan, etc.) give their submarines names. The no-name policy seems most suited to a force that wishes to disguise the true extent of its capabilities, or lack thereof. This hardly seems necessary for China today when she has both a large and reasonably modern force.
The similarity with FACs also seems outdated, particularly when it comes to SSNs and SSBNs. The 094 SSBNs are larger than 052D destroyers! Even the Kilo and Yuan type SSKs are significantly larger than the 056 corvettes which are given names.
My opinion is of no relevance, but I would be glad to see this policy disappear, and these platforms earn just the psychological connection you refer to, befitting their importance to the nation.