If company or cc is dormant, should they submit FAS?

Yes, a FAS in this case is compulsory irrespective of trading status and revenue.

This will also give CIPC a contact person when the entity is going to be deregistered.

Disclaimer:

Please note that the information provided does not constitute legal or professional advice, but rather the applicability of existing theory to a given practical situation. Due care is taken to ensure that the information is correct, but it remains subjective and an interpretation of application of information.