You will have to ask him from whom you heard it to support such an incredible claim.
What the code does legislate is this:
Can. 6 §1. When this Code takes force, the following are abrogated:
1/ the Code of Canon Law promulgated in 1917;
2/ other universal or particular laws contrary to the prescripts of this Code unless other provision is expressly made for particular laws;
3/ any universal or particular penal laws whatsoever issued by the Apostolic See unless they are contained in this Code;
4/ other universal disciplinary laws regarding matter which this Code completely reorders.
§2. Insofar as they repeat former law, the canons of this Code must be assessed also in accord with canonical tradition.
I AM NOT A CANON LAWYER, but it seems to me that 6.1.1 would indicate, eg, the headcovering statues from 1917 are abrogated.