To my understanding, I think, this rule has now been implemented.

Implemented in 'good cause' means, DHS assumes that their decision is benificial to the public. Note that the decision was made because of total of 17 senators requested the extension. However, if another group of senators raise issues in this decision, then DHS may take back this 'interim rule' for another 'good cause'. This is just a statement from DHS ensuring that everyone will be heard. At this situation, I do not think they will change their decision.

Any other decisions about H1B, OPT period which will be passed as a 'bill' will override such interim rule.

I do not know in detail about implementing or scrubbing the 'interim rule'. Its just my common sense.